static electricity “electrostatics”
DESCRIPTION
Static Electricity “Electrostatics”. “Static”- not moving. Electric charges that can be collected and held in one place Examples: sparks on carpet, balloon against hair, lightning, photocopier - PowerPoint PPT PresentationTRANSCRIPT
Static ElectricityldquoElectrostaticsrdquo
bull ldquoStaticrdquo- not moving Electric charges that can be collected and held in one place
ndash Examples sparks on carpet balloon against hair lightning photocopier
ndash History ancient Greeks made little sparks when rubbing amber with fur (Greek word for amber ldquoelektronrdquo)
ndash Electric charge ldquoqrdquo is measured in Coulombs C One Coulomb is charge is a dangerously high charge An average lightning bolt has about 10 Coulombs of charge
bull Atomic Viewndash Proton in nucleus
bull Positive chargebull q = + 16 x 10-19 C
ndash Electron outside nucleusbull Negative chargebull q = - 16 x 10-19 C
ndash Protons and Electrons have the same amount of charge but a proton has much more mass
ndash Neutron in nucleus has no chargendash Molecules
bull 2 or more atoms bonded togetherbull usually atoms and molecules are neutral
but if they have a net charge they are called IONS
bull Behavior of chargesndash Unlike charges attractndash Like charges repelndash A neutral object will attract both positive
and negative charges
Charles Coulomb mid 1700rsquos studied and published papers about the electrostatic force between 2 charged objects
Ben Franklin was the first to use the terms ldquopositiverdquo and ldquonegativerdquo to describe electrical charge Mid 1700rsquos
Hmmm+ + +- - -
Robert Millikan
First determined the ldquoelementary chargerdquo- the charge on an electron or proton (early 1900rsquos)
MaterialsConductors
bull Substances that have easily moveable electric charges
bull Most familiar conductors are metals that have ldquofree electronsrdquo
bull Positive ions may also be mobile
ndash Insulatorsbull Charges cannot move
easilybull Examples plastic wood
glass
Semiconductor used in computers
Conduction is an intermediate magnitude between a conductor and an insulator
Superconductor NO resistance to the flow of electrons So far no material is a superconductor except at extremely low temperatures
ndash Water insulator or conductorbull PURE water does NOT conduct electricitybull Impurities or ions in water can allow conductionbull The purer the water the lower the conductivitybull (the conduction of electricity is called
ELECTROLYTIC behavior- )ndash Air insulator or conductor
bull Usually an insulator thankfullybull When strong forces are present electronrsquos can be
stripped from air molecules creating ionsbull example lightning
LightningAn electrical discharge between the clouds
and the ground or between two clouds
As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING
The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)
We call that THUNDER
How much electrical charge is flowing through a lightning bolt
Typically around 10 Coulombs of chargeHow many electrons each with a negative
charge of 16 x 10-19 C does it take to have 10 C of charge
10 C 16 x 10-19 C =625 x 1019 electrons
How many electrons are flowing in a 12 C lightning bolt
75 x 1019 electrons
The Earth is able to absorb much electrical charge
Touching a charged object to the Earth in order to discharge it is called
GROUNDING
bull Methods to electrically charge an object
ndash Conduction bull Direct contact will transfer
electrons such as touching your car door in the winter
bull Friction rubbing your feet against carpet hair against a balloon
ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object
near but not in contact with a neutral object
bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object
bull If provided a pathway the separated electrons will leave
bull The object is now positively charged
bull Electrostatics devicesndash Electroscope the
separation of metal leaves indicates the presence of static charge
ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome
ndash Electrophorus a device used to transfer electric charge
Coulombrsquos Lawndash Calculates the magnitude
of the electric force between two charges
ndash Each charge experiences equal but opposite forces
k is a constant k = 9 x 109 Nm2C2
221
dqqkF
(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)
Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation
221
dmmGF 2
21dqqkF
Differences 1 Gravitational Force is based on MASS
Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force
The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively
small forceldquokrdquo is a huge number therefore electric force is a
relatively large force
Both laws are INVERSE SQUARE LAWSldquoThe Force varies with the inverse of the
distance squaredrdquoAt twice the distance d2 = 22 in denominator = frac14 the ForceAt three times the distance 32 in denominator= 19 the ForceAt half the distance (12)2 in denominator= 4 times the ForceNow if one CHARGE q doubleshellip The Force
doubles since they are directly related
221
dqqkF
Get a calculator and letrsquos practice onehellip
What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)USE THE EXPONENT BUTTONF = 9E9 32E-3 248E-6 divide 24E-3 2 F = 124000000 N
or for Quest 124E8or 124e8
221
dqqkF
RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge
+-
+
Get a clicker and calculator Log in and get ready to answer some questions
1 Electric Charge is measured inA AmpsB VoltsC CoulombsD Farads
2 Opposite chargesA AttractB RepelC May attract or repel depending on their
relative sizeD Neither attract nor repel
3 Objects with a neutral charge are A Attracted only by objects with a net
positive chargeB Attracted only by objects with a net
negative chargeC Not attracted by any kind of chargeD Attracted by objects with either positive or
negative charge
The charge of one electron = - 16 x 10-19 C
4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)
5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of
A 3B 6C 9D 13E 16F 19
221
dqqkF
- Static Electricity ldquoElectrostaticsrdquo
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Robert Millikan
- Slide 8
- Slide 9
- Slide 10
- Lightning
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Get a calculator and letrsquos practice onehellip
- RememberhellipForce is a VECTOR- it always points in a specific dir
- Slide 23
- Get a clicker and calculator Log in and get ready to answer s
- Slide 25
- Slide 26
- The charge of one electron = - 16 x 10-19 C
- Slide 28
-
bull ldquoStaticrdquo- not moving Electric charges that can be collected and held in one place
ndash Examples sparks on carpet balloon against hair lightning photocopier
ndash History ancient Greeks made little sparks when rubbing amber with fur (Greek word for amber ldquoelektronrdquo)
ndash Electric charge ldquoqrdquo is measured in Coulombs C One Coulomb is charge is a dangerously high charge An average lightning bolt has about 10 Coulombs of charge
bull Atomic Viewndash Proton in nucleus
bull Positive chargebull q = + 16 x 10-19 C
ndash Electron outside nucleusbull Negative chargebull q = - 16 x 10-19 C
ndash Protons and Electrons have the same amount of charge but a proton has much more mass
ndash Neutron in nucleus has no chargendash Molecules
bull 2 or more atoms bonded togetherbull usually atoms and molecules are neutral
but if they have a net charge they are called IONS
bull Behavior of chargesndash Unlike charges attractndash Like charges repelndash A neutral object will attract both positive
and negative charges
Charles Coulomb mid 1700rsquos studied and published papers about the electrostatic force between 2 charged objects
Ben Franklin was the first to use the terms ldquopositiverdquo and ldquonegativerdquo to describe electrical charge Mid 1700rsquos
Hmmm+ + +- - -
Robert Millikan
First determined the ldquoelementary chargerdquo- the charge on an electron or proton (early 1900rsquos)
MaterialsConductors
bull Substances that have easily moveable electric charges
bull Most familiar conductors are metals that have ldquofree electronsrdquo
bull Positive ions may also be mobile
ndash Insulatorsbull Charges cannot move
easilybull Examples plastic wood
glass
Semiconductor used in computers
Conduction is an intermediate magnitude between a conductor and an insulator
Superconductor NO resistance to the flow of electrons So far no material is a superconductor except at extremely low temperatures
ndash Water insulator or conductorbull PURE water does NOT conduct electricitybull Impurities or ions in water can allow conductionbull The purer the water the lower the conductivitybull (the conduction of electricity is called
ELECTROLYTIC behavior- )ndash Air insulator or conductor
bull Usually an insulator thankfullybull When strong forces are present electronrsquos can be
stripped from air molecules creating ionsbull example lightning
LightningAn electrical discharge between the clouds
and the ground or between two clouds
As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING
The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)
We call that THUNDER
How much electrical charge is flowing through a lightning bolt
Typically around 10 Coulombs of chargeHow many electrons each with a negative
charge of 16 x 10-19 C does it take to have 10 C of charge
10 C 16 x 10-19 C =625 x 1019 electrons
How many electrons are flowing in a 12 C lightning bolt
75 x 1019 electrons
The Earth is able to absorb much electrical charge
Touching a charged object to the Earth in order to discharge it is called
GROUNDING
bull Methods to electrically charge an object
ndash Conduction bull Direct contact will transfer
electrons such as touching your car door in the winter
bull Friction rubbing your feet against carpet hair against a balloon
ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object
near but not in contact with a neutral object
bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object
bull If provided a pathway the separated electrons will leave
bull The object is now positively charged
bull Electrostatics devicesndash Electroscope the
separation of metal leaves indicates the presence of static charge
ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome
ndash Electrophorus a device used to transfer electric charge
Coulombrsquos Lawndash Calculates the magnitude
of the electric force between two charges
ndash Each charge experiences equal but opposite forces
k is a constant k = 9 x 109 Nm2C2
221
dqqkF
(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)
Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation
221
dmmGF 2
21dqqkF
Differences 1 Gravitational Force is based on MASS
Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force
The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively
small forceldquokrdquo is a huge number therefore electric force is a
relatively large force
Both laws are INVERSE SQUARE LAWSldquoThe Force varies with the inverse of the
distance squaredrdquoAt twice the distance d2 = 22 in denominator = frac14 the ForceAt three times the distance 32 in denominator= 19 the ForceAt half the distance (12)2 in denominator= 4 times the ForceNow if one CHARGE q doubleshellip The Force
doubles since they are directly related
221
dqqkF
Get a calculator and letrsquos practice onehellip
What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)USE THE EXPONENT BUTTONF = 9E9 32E-3 248E-6 divide 24E-3 2 F = 124000000 N
or for Quest 124E8or 124e8
221
dqqkF
RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge
+-
+
Get a clicker and calculator Log in and get ready to answer some questions
1 Electric Charge is measured inA AmpsB VoltsC CoulombsD Farads
2 Opposite chargesA AttractB RepelC May attract or repel depending on their
relative sizeD Neither attract nor repel
3 Objects with a neutral charge are A Attracted only by objects with a net
positive chargeB Attracted only by objects with a net
negative chargeC Not attracted by any kind of chargeD Attracted by objects with either positive or
negative charge
The charge of one electron = - 16 x 10-19 C
4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)
5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of
A 3B 6C 9D 13E 16F 19
221
dqqkF
- Static Electricity ldquoElectrostaticsrdquo
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Robert Millikan
- Slide 8
- Slide 9
- Slide 10
- Lightning
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Get a calculator and letrsquos practice onehellip
- RememberhellipForce is a VECTOR- it always points in a specific dir
- Slide 23
- Get a clicker and calculator Log in and get ready to answer s
- Slide 25
- Slide 26
- The charge of one electron = - 16 x 10-19 C
- Slide 28
-
bull Atomic Viewndash Proton in nucleus
bull Positive chargebull q = + 16 x 10-19 C
ndash Electron outside nucleusbull Negative chargebull q = - 16 x 10-19 C
ndash Protons and Electrons have the same amount of charge but a proton has much more mass
ndash Neutron in nucleus has no chargendash Molecules
bull 2 or more atoms bonded togetherbull usually atoms and molecules are neutral
but if they have a net charge they are called IONS
bull Behavior of chargesndash Unlike charges attractndash Like charges repelndash A neutral object will attract both positive
and negative charges
Charles Coulomb mid 1700rsquos studied and published papers about the electrostatic force between 2 charged objects
Ben Franklin was the first to use the terms ldquopositiverdquo and ldquonegativerdquo to describe electrical charge Mid 1700rsquos
Hmmm+ + +- - -
Robert Millikan
First determined the ldquoelementary chargerdquo- the charge on an electron or proton (early 1900rsquos)
MaterialsConductors
bull Substances that have easily moveable electric charges
bull Most familiar conductors are metals that have ldquofree electronsrdquo
bull Positive ions may also be mobile
ndash Insulatorsbull Charges cannot move
easilybull Examples plastic wood
glass
Semiconductor used in computers
Conduction is an intermediate magnitude between a conductor and an insulator
Superconductor NO resistance to the flow of electrons So far no material is a superconductor except at extremely low temperatures
ndash Water insulator or conductorbull PURE water does NOT conduct electricitybull Impurities or ions in water can allow conductionbull The purer the water the lower the conductivitybull (the conduction of electricity is called
ELECTROLYTIC behavior- )ndash Air insulator or conductor
bull Usually an insulator thankfullybull When strong forces are present electronrsquos can be
stripped from air molecules creating ionsbull example lightning
LightningAn electrical discharge between the clouds
and the ground or between two clouds
As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING
The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)
We call that THUNDER
How much electrical charge is flowing through a lightning bolt
Typically around 10 Coulombs of chargeHow many electrons each with a negative
charge of 16 x 10-19 C does it take to have 10 C of charge
10 C 16 x 10-19 C =625 x 1019 electrons
How many electrons are flowing in a 12 C lightning bolt
75 x 1019 electrons
The Earth is able to absorb much electrical charge
Touching a charged object to the Earth in order to discharge it is called
GROUNDING
bull Methods to electrically charge an object
ndash Conduction bull Direct contact will transfer
electrons such as touching your car door in the winter
bull Friction rubbing your feet against carpet hair against a balloon
ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object
near but not in contact with a neutral object
bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object
bull If provided a pathway the separated electrons will leave
bull The object is now positively charged
bull Electrostatics devicesndash Electroscope the
separation of metal leaves indicates the presence of static charge
ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome
ndash Electrophorus a device used to transfer electric charge
Coulombrsquos Lawndash Calculates the magnitude
of the electric force between two charges
ndash Each charge experiences equal but opposite forces
k is a constant k = 9 x 109 Nm2C2
221
dqqkF
(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)
Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation
221
dmmGF 2
21dqqkF
Differences 1 Gravitational Force is based on MASS
Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force
The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively
small forceldquokrdquo is a huge number therefore electric force is a
relatively large force
Both laws are INVERSE SQUARE LAWSldquoThe Force varies with the inverse of the
distance squaredrdquoAt twice the distance d2 = 22 in denominator = frac14 the ForceAt three times the distance 32 in denominator= 19 the ForceAt half the distance (12)2 in denominator= 4 times the ForceNow if one CHARGE q doubleshellip The Force
doubles since they are directly related
221
dqqkF
Get a calculator and letrsquos practice onehellip
What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)USE THE EXPONENT BUTTONF = 9E9 32E-3 248E-6 divide 24E-3 2 F = 124000000 N
or for Quest 124E8or 124e8
221
dqqkF
RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge
+-
+
Get a clicker and calculator Log in and get ready to answer some questions
1 Electric Charge is measured inA AmpsB VoltsC CoulombsD Farads
2 Opposite chargesA AttractB RepelC May attract or repel depending on their
relative sizeD Neither attract nor repel
3 Objects with a neutral charge are A Attracted only by objects with a net
positive chargeB Attracted only by objects with a net
negative chargeC Not attracted by any kind of chargeD Attracted by objects with either positive or
negative charge
The charge of one electron = - 16 x 10-19 C
4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)
5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of
A 3B 6C 9D 13E 16F 19
221
dqqkF
- Static Electricity ldquoElectrostaticsrdquo
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Robert Millikan
- Slide 8
- Slide 9
- Slide 10
- Lightning
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Get a calculator and letrsquos practice onehellip
- RememberhellipForce is a VECTOR- it always points in a specific dir
- Slide 23
- Get a clicker and calculator Log in and get ready to answer s
- Slide 25
- Slide 26
- The charge of one electron = - 16 x 10-19 C
- Slide 28
-
bull Behavior of chargesndash Unlike charges attractndash Like charges repelndash A neutral object will attract both positive
and negative charges
Charles Coulomb mid 1700rsquos studied and published papers about the electrostatic force between 2 charged objects
Ben Franklin was the first to use the terms ldquopositiverdquo and ldquonegativerdquo to describe electrical charge Mid 1700rsquos
Hmmm+ + +- - -
Robert Millikan
First determined the ldquoelementary chargerdquo- the charge on an electron or proton (early 1900rsquos)
MaterialsConductors
bull Substances that have easily moveable electric charges
bull Most familiar conductors are metals that have ldquofree electronsrdquo
bull Positive ions may also be mobile
ndash Insulatorsbull Charges cannot move
easilybull Examples plastic wood
glass
Semiconductor used in computers
Conduction is an intermediate magnitude between a conductor and an insulator
Superconductor NO resistance to the flow of electrons So far no material is a superconductor except at extremely low temperatures
ndash Water insulator or conductorbull PURE water does NOT conduct electricitybull Impurities or ions in water can allow conductionbull The purer the water the lower the conductivitybull (the conduction of electricity is called
ELECTROLYTIC behavior- )ndash Air insulator or conductor
bull Usually an insulator thankfullybull When strong forces are present electronrsquos can be
stripped from air molecules creating ionsbull example lightning
LightningAn electrical discharge between the clouds
and the ground or between two clouds
As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING
The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)
We call that THUNDER
How much electrical charge is flowing through a lightning bolt
Typically around 10 Coulombs of chargeHow many electrons each with a negative
charge of 16 x 10-19 C does it take to have 10 C of charge
10 C 16 x 10-19 C =625 x 1019 electrons
How many electrons are flowing in a 12 C lightning bolt
75 x 1019 electrons
The Earth is able to absorb much electrical charge
Touching a charged object to the Earth in order to discharge it is called
GROUNDING
bull Methods to electrically charge an object
ndash Conduction bull Direct contact will transfer
electrons such as touching your car door in the winter
bull Friction rubbing your feet against carpet hair against a balloon
ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object
near but not in contact with a neutral object
bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object
bull If provided a pathway the separated electrons will leave
bull The object is now positively charged
bull Electrostatics devicesndash Electroscope the
separation of metal leaves indicates the presence of static charge
ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome
ndash Electrophorus a device used to transfer electric charge
Coulombrsquos Lawndash Calculates the magnitude
of the electric force between two charges
ndash Each charge experiences equal but opposite forces
k is a constant k = 9 x 109 Nm2C2
221
dqqkF
(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)
Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation
221
dmmGF 2
21dqqkF
Differences 1 Gravitational Force is based on MASS
Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force
The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively
small forceldquokrdquo is a huge number therefore electric force is a
relatively large force
Both laws are INVERSE SQUARE LAWSldquoThe Force varies with the inverse of the
distance squaredrdquoAt twice the distance d2 = 22 in denominator = frac14 the ForceAt three times the distance 32 in denominator= 19 the ForceAt half the distance (12)2 in denominator= 4 times the ForceNow if one CHARGE q doubleshellip The Force
doubles since they are directly related
221
dqqkF
Get a calculator and letrsquos practice onehellip
What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)USE THE EXPONENT BUTTONF = 9E9 32E-3 248E-6 divide 24E-3 2 F = 124000000 N
or for Quest 124E8or 124e8
221
dqqkF
RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge
+-
+
Get a clicker and calculator Log in and get ready to answer some questions
1 Electric Charge is measured inA AmpsB VoltsC CoulombsD Farads
2 Opposite chargesA AttractB RepelC May attract or repel depending on their
relative sizeD Neither attract nor repel
3 Objects with a neutral charge are A Attracted only by objects with a net
positive chargeB Attracted only by objects with a net
negative chargeC Not attracted by any kind of chargeD Attracted by objects with either positive or
negative charge
The charge of one electron = - 16 x 10-19 C
4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)
5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of
A 3B 6C 9D 13E 16F 19
221
dqqkF
- Static Electricity ldquoElectrostaticsrdquo
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Robert Millikan
- Slide 8
- Slide 9
- Slide 10
- Lightning
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Get a calculator and letrsquos practice onehellip
- RememberhellipForce is a VECTOR- it always points in a specific dir
- Slide 23
- Get a clicker and calculator Log in and get ready to answer s
- Slide 25
- Slide 26
- The charge of one electron = - 16 x 10-19 C
- Slide 28
-
Charles Coulomb mid 1700rsquos studied and published papers about the electrostatic force between 2 charged objects
Ben Franklin was the first to use the terms ldquopositiverdquo and ldquonegativerdquo to describe electrical charge Mid 1700rsquos
Hmmm+ + +- - -
Robert Millikan
First determined the ldquoelementary chargerdquo- the charge on an electron or proton (early 1900rsquos)
MaterialsConductors
bull Substances that have easily moveable electric charges
bull Most familiar conductors are metals that have ldquofree electronsrdquo
bull Positive ions may also be mobile
ndash Insulatorsbull Charges cannot move
easilybull Examples plastic wood
glass
Semiconductor used in computers
Conduction is an intermediate magnitude between a conductor and an insulator
Superconductor NO resistance to the flow of electrons So far no material is a superconductor except at extremely low temperatures
ndash Water insulator or conductorbull PURE water does NOT conduct electricitybull Impurities or ions in water can allow conductionbull The purer the water the lower the conductivitybull (the conduction of electricity is called
ELECTROLYTIC behavior- )ndash Air insulator or conductor
bull Usually an insulator thankfullybull When strong forces are present electronrsquos can be
stripped from air molecules creating ionsbull example lightning
LightningAn electrical discharge between the clouds
and the ground or between two clouds
As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING
The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)
We call that THUNDER
How much electrical charge is flowing through a lightning bolt
Typically around 10 Coulombs of chargeHow many electrons each with a negative
charge of 16 x 10-19 C does it take to have 10 C of charge
10 C 16 x 10-19 C =625 x 1019 electrons
How many electrons are flowing in a 12 C lightning bolt
75 x 1019 electrons
The Earth is able to absorb much electrical charge
Touching a charged object to the Earth in order to discharge it is called
GROUNDING
bull Methods to electrically charge an object
ndash Conduction bull Direct contact will transfer
electrons such as touching your car door in the winter
bull Friction rubbing your feet against carpet hair against a balloon
ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object
near but not in contact with a neutral object
bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object
bull If provided a pathway the separated electrons will leave
bull The object is now positively charged
bull Electrostatics devicesndash Electroscope the
separation of metal leaves indicates the presence of static charge
ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome
ndash Electrophorus a device used to transfer electric charge
Coulombrsquos Lawndash Calculates the magnitude
of the electric force between two charges
ndash Each charge experiences equal but opposite forces
k is a constant k = 9 x 109 Nm2C2
221
dqqkF
(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)
Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation
221
dmmGF 2
21dqqkF
Differences 1 Gravitational Force is based on MASS
Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force
The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively
small forceldquokrdquo is a huge number therefore electric force is a
relatively large force
Both laws are INVERSE SQUARE LAWSldquoThe Force varies with the inverse of the
distance squaredrdquoAt twice the distance d2 = 22 in denominator = frac14 the ForceAt three times the distance 32 in denominator= 19 the ForceAt half the distance (12)2 in denominator= 4 times the ForceNow if one CHARGE q doubleshellip The Force
doubles since they are directly related
221
dqqkF
Get a calculator and letrsquos practice onehellip
What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)USE THE EXPONENT BUTTONF = 9E9 32E-3 248E-6 divide 24E-3 2 F = 124000000 N
or for Quest 124E8or 124e8
221
dqqkF
RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge
+-
+
Get a clicker and calculator Log in and get ready to answer some questions
1 Electric Charge is measured inA AmpsB VoltsC CoulombsD Farads
2 Opposite chargesA AttractB RepelC May attract or repel depending on their
relative sizeD Neither attract nor repel
3 Objects with a neutral charge are A Attracted only by objects with a net
positive chargeB Attracted only by objects with a net
negative chargeC Not attracted by any kind of chargeD Attracted by objects with either positive or
negative charge
The charge of one electron = - 16 x 10-19 C
4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)
5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of
A 3B 6C 9D 13E 16F 19
221
dqqkF
- Static Electricity ldquoElectrostaticsrdquo
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Robert Millikan
- Slide 8
- Slide 9
- Slide 10
- Lightning
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Get a calculator and letrsquos practice onehellip
- RememberhellipForce is a VECTOR- it always points in a specific dir
- Slide 23
- Get a clicker and calculator Log in and get ready to answer s
- Slide 25
- Slide 26
- The charge of one electron = - 16 x 10-19 C
- Slide 28
-
Ben Franklin was the first to use the terms ldquopositiverdquo and ldquonegativerdquo to describe electrical charge Mid 1700rsquos
Hmmm+ + +- - -
Robert Millikan
First determined the ldquoelementary chargerdquo- the charge on an electron or proton (early 1900rsquos)
MaterialsConductors
bull Substances that have easily moveable electric charges
bull Most familiar conductors are metals that have ldquofree electronsrdquo
bull Positive ions may also be mobile
ndash Insulatorsbull Charges cannot move
easilybull Examples plastic wood
glass
Semiconductor used in computers
Conduction is an intermediate magnitude between a conductor and an insulator
Superconductor NO resistance to the flow of electrons So far no material is a superconductor except at extremely low temperatures
ndash Water insulator or conductorbull PURE water does NOT conduct electricitybull Impurities or ions in water can allow conductionbull The purer the water the lower the conductivitybull (the conduction of electricity is called
ELECTROLYTIC behavior- )ndash Air insulator or conductor
bull Usually an insulator thankfullybull When strong forces are present electronrsquos can be
stripped from air molecules creating ionsbull example lightning
LightningAn electrical discharge between the clouds
and the ground or between two clouds
As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING
The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)
We call that THUNDER
How much electrical charge is flowing through a lightning bolt
Typically around 10 Coulombs of chargeHow many electrons each with a negative
charge of 16 x 10-19 C does it take to have 10 C of charge
10 C 16 x 10-19 C =625 x 1019 electrons
How many electrons are flowing in a 12 C lightning bolt
75 x 1019 electrons
The Earth is able to absorb much electrical charge
Touching a charged object to the Earth in order to discharge it is called
GROUNDING
bull Methods to electrically charge an object
ndash Conduction bull Direct contact will transfer
electrons such as touching your car door in the winter
bull Friction rubbing your feet against carpet hair against a balloon
ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object
near but not in contact with a neutral object
bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object
bull If provided a pathway the separated electrons will leave
bull The object is now positively charged
bull Electrostatics devicesndash Electroscope the
separation of metal leaves indicates the presence of static charge
ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome
ndash Electrophorus a device used to transfer electric charge
Coulombrsquos Lawndash Calculates the magnitude
of the electric force between two charges
ndash Each charge experiences equal but opposite forces
k is a constant k = 9 x 109 Nm2C2
221
dqqkF
(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)
Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation
221
dmmGF 2
21dqqkF
Differences 1 Gravitational Force is based on MASS
Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force
The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively
small forceldquokrdquo is a huge number therefore electric force is a
relatively large force
Both laws are INVERSE SQUARE LAWSldquoThe Force varies with the inverse of the
distance squaredrdquoAt twice the distance d2 = 22 in denominator = frac14 the ForceAt three times the distance 32 in denominator= 19 the ForceAt half the distance (12)2 in denominator= 4 times the ForceNow if one CHARGE q doubleshellip The Force
doubles since they are directly related
221
dqqkF
Get a calculator and letrsquos practice onehellip
What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)USE THE EXPONENT BUTTONF = 9E9 32E-3 248E-6 divide 24E-3 2 F = 124000000 N
or for Quest 124E8or 124e8
221
dqqkF
RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge
+-
+
Get a clicker and calculator Log in and get ready to answer some questions
1 Electric Charge is measured inA AmpsB VoltsC CoulombsD Farads
2 Opposite chargesA AttractB RepelC May attract or repel depending on their
relative sizeD Neither attract nor repel
3 Objects with a neutral charge are A Attracted only by objects with a net
positive chargeB Attracted only by objects with a net
negative chargeC Not attracted by any kind of chargeD Attracted by objects with either positive or
negative charge
The charge of one electron = - 16 x 10-19 C
4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)
5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of
A 3B 6C 9D 13E 16F 19
221
dqqkF
- Static Electricity ldquoElectrostaticsrdquo
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Robert Millikan
- Slide 8
- Slide 9
- Slide 10
- Lightning
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Get a calculator and letrsquos practice onehellip
- RememberhellipForce is a VECTOR- it always points in a specific dir
- Slide 23
- Get a clicker and calculator Log in and get ready to answer s
- Slide 25
- Slide 26
- The charge of one electron = - 16 x 10-19 C
- Slide 28
-
Robert Millikan
First determined the ldquoelementary chargerdquo- the charge on an electron or proton (early 1900rsquos)
MaterialsConductors
bull Substances that have easily moveable electric charges
bull Most familiar conductors are metals that have ldquofree electronsrdquo
bull Positive ions may also be mobile
ndash Insulatorsbull Charges cannot move
easilybull Examples plastic wood
glass
Semiconductor used in computers
Conduction is an intermediate magnitude between a conductor and an insulator
Superconductor NO resistance to the flow of electrons So far no material is a superconductor except at extremely low temperatures
ndash Water insulator or conductorbull PURE water does NOT conduct electricitybull Impurities or ions in water can allow conductionbull The purer the water the lower the conductivitybull (the conduction of electricity is called
ELECTROLYTIC behavior- )ndash Air insulator or conductor
bull Usually an insulator thankfullybull When strong forces are present electronrsquos can be
stripped from air molecules creating ionsbull example lightning
LightningAn electrical discharge between the clouds
and the ground or between two clouds
As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING
The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)
We call that THUNDER
How much electrical charge is flowing through a lightning bolt
Typically around 10 Coulombs of chargeHow many electrons each with a negative
charge of 16 x 10-19 C does it take to have 10 C of charge
10 C 16 x 10-19 C =625 x 1019 electrons
How many electrons are flowing in a 12 C lightning bolt
75 x 1019 electrons
The Earth is able to absorb much electrical charge
Touching a charged object to the Earth in order to discharge it is called
GROUNDING
bull Methods to electrically charge an object
ndash Conduction bull Direct contact will transfer
electrons such as touching your car door in the winter
bull Friction rubbing your feet against carpet hair against a balloon
ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object
near but not in contact with a neutral object
bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object
bull If provided a pathway the separated electrons will leave
bull The object is now positively charged
bull Electrostatics devicesndash Electroscope the
separation of metal leaves indicates the presence of static charge
ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome
ndash Electrophorus a device used to transfer electric charge
Coulombrsquos Lawndash Calculates the magnitude
of the electric force between two charges
ndash Each charge experiences equal but opposite forces
k is a constant k = 9 x 109 Nm2C2
221
dqqkF
(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)
Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation
221
dmmGF 2
21dqqkF
Differences 1 Gravitational Force is based on MASS
Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force
The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively
small forceldquokrdquo is a huge number therefore electric force is a
relatively large force
Both laws are INVERSE SQUARE LAWSldquoThe Force varies with the inverse of the
distance squaredrdquoAt twice the distance d2 = 22 in denominator = frac14 the ForceAt three times the distance 32 in denominator= 19 the ForceAt half the distance (12)2 in denominator= 4 times the ForceNow if one CHARGE q doubleshellip The Force
doubles since they are directly related
221
dqqkF
Get a calculator and letrsquos practice onehellip
What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)USE THE EXPONENT BUTTONF = 9E9 32E-3 248E-6 divide 24E-3 2 F = 124000000 N
or for Quest 124E8or 124e8
221
dqqkF
RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge
+-
+
Get a clicker and calculator Log in and get ready to answer some questions
1 Electric Charge is measured inA AmpsB VoltsC CoulombsD Farads
2 Opposite chargesA AttractB RepelC May attract or repel depending on their
relative sizeD Neither attract nor repel
3 Objects with a neutral charge are A Attracted only by objects with a net
positive chargeB Attracted only by objects with a net
negative chargeC Not attracted by any kind of chargeD Attracted by objects with either positive or
negative charge
The charge of one electron = - 16 x 10-19 C
4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)
5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of
A 3B 6C 9D 13E 16F 19
221
dqqkF
- Static Electricity ldquoElectrostaticsrdquo
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Robert Millikan
- Slide 8
- Slide 9
- Slide 10
- Lightning
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Get a calculator and letrsquos practice onehellip
- RememberhellipForce is a VECTOR- it always points in a specific dir
- Slide 23
- Get a clicker and calculator Log in and get ready to answer s
- Slide 25
- Slide 26
- The charge of one electron = - 16 x 10-19 C
- Slide 28
-
MaterialsConductors
bull Substances that have easily moveable electric charges
bull Most familiar conductors are metals that have ldquofree electronsrdquo
bull Positive ions may also be mobile
ndash Insulatorsbull Charges cannot move
easilybull Examples plastic wood
glass
Semiconductor used in computers
Conduction is an intermediate magnitude between a conductor and an insulator
Superconductor NO resistance to the flow of electrons So far no material is a superconductor except at extremely low temperatures
ndash Water insulator or conductorbull PURE water does NOT conduct electricitybull Impurities or ions in water can allow conductionbull The purer the water the lower the conductivitybull (the conduction of electricity is called
ELECTROLYTIC behavior- )ndash Air insulator or conductor
bull Usually an insulator thankfullybull When strong forces are present electronrsquos can be
stripped from air molecules creating ionsbull example lightning
LightningAn electrical discharge between the clouds
and the ground or between two clouds
As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING
The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)
We call that THUNDER
How much electrical charge is flowing through a lightning bolt
Typically around 10 Coulombs of chargeHow many electrons each with a negative
charge of 16 x 10-19 C does it take to have 10 C of charge
10 C 16 x 10-19 C =625 x 1019 electrons
How many electrons are flowing in a 12 C lightning bolt
75 x 1019 electrons
The Earth is able to absorb much electrical charge
Touching a charged object to the Earth in order to discharge it is called
GROUNDING
bull Methods to electrically charge an object
ndash Conduction bull Direct contact will transfer
electrons such as touching your car door in the winter
bull Friction rubbing your feet against carpet hair against a balloon
ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object
near but not in contact with a neutral object
bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object
bull If provided a pathway the separated electrons will leave
bull The object is now positively charged
bull Electrostatics devicesndash Electroscope the
separation of metal leaves indicates the presence of static charge
ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome
ndash Electrophorus a device used to transfer electric charge
Coulombrsquos Lawndash Calculates the magnitude
of the electric force between two charges
ndash Each charge experiences equal but opposite forces
k is a constant k = 9 x 109 Nm2C2
221
dqqkF
(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)
Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation
221
dmmGF 2
21dqqkF
Differences 1 Gravitational Force is based on MASS
Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force
The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively
small forceldquokrdquo is a huge number therefore electric force is a
relatively large force
Both laws are INVERSE SQUARE LAWSldquoThe Force varies with the inverse of the
distance squaredrdquoAt twice the distance d2 = 22 in denominator = frac14 the ForceAt three times the distance 32 in denominator= 19 the ForceAt half the distance (12)2 in denominator= 4 times the ForceNow if one CHARGE q doubleshellip The Force
doubles since they are directly related
221
dqqkF
Get a calculator and letrsquos practice onehellip
What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)USE THE EXPONENT BUTTONF = 9E9 32E-3 248E-6 divide 24E-3 2 F = 124000000 N
or for Quest 124E8or 124e8
221
dqqkF
RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge
+-
+
Get a clicker and calculator Log in and get ready to answer some questions
1 Electric Charge is measured inA AmpsB VoltsC CoulombsD Farads
2 Opposite chargesA AttractB RepelC May attract or repel depending on their
relative sizeD Neither attract nor repel
3 Objects with a neutral charge are A Attracted only by objects with a net
positive chargeB Attracted only by objects with a net
negative chargeC Not attracted by any kind of chargeD Attracted by objects with either positive or
negative charge
The charge of one electron = - 16 x 10-19 C
4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)
5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of
A 3B 6C 9D 13E 16F 19
221
dqqkF
- Static Electricity ldquoElectrostaticsrdquo
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Robert Millikan
- Slide 8
- Slide 9
- Slide 10
- Lightning
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Get a calculator and letrsquos practice onehellip
- RememberhellipForce is a VECTOR- it always points in a specific dir
- Slide 23
- Get a clicker and calculator Log in and get ready to answer s
- Slide 25
- Slide 26
- The charge of one electron = - 16 x 10-19 C
- Slide 28
-
Semiconductor used in computers
Conduction is an intermediate magnitude between a conductor and an insulator
Superconductor NO resistance to the flow of electrons So far no material is a superconductor except at extremely low temperatures
ndash Water insulator or conductorbull PURE water does NOT conduct electricitybull Impurities or ions in water can allow conductionbull The purer the water the lower the conductivitybull (the conduction of electricity is called
ELECTROLYTIC behavior- )ndash Air insulator or conductor
bull Usually an insulator thankfullybull When strong forces are present electronrsquos can be
stripped from air molecules creating ionsbull example lightning
LightningAn electrical discharge between the clouds
and the ground or between two clouds
As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING
The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)
We call that THUNDER
How much electrical charge is flowing through a lightning bolt
Typically around 10 Coulombs of chargeHow many electrons each with a negative
charge of 16 x 10-19 C does it take to have 10 C of charge
10 C 16 x 10-19 C =625 x 1019 electrons
How many electrons are flowing in a 12 C lightning bolt
75 x 1019 electrons
The Earth is able to absorb much electrical charge
Touching a charged object to the Earth in order to discharge it is called
GROUNDING
bull Methods to electrically charge an object
ndash Conduction bull Direct contact will transfer
electrons such as touching your car door in the winter
bull Friction rubbing your feet against carpet hair against a balloon
ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object
near but not in contact with a neutral object
bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object
bull If provided a pathway the separated electrons will leave
bull The object is now positively charged
bull Electrostatics devicesndash Electroscope the
separation of metal leaves indicates the presence of static charge
ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome
ndash Electrophorus a device used to transfer electric charge
Coulombrsquos Lawndash Calculates the magnitude
of the electric force between two charges
ndash Each charge experiences equal but opposite forces
k is a constant k = 9 x 109 Nm2C2
221
dqqkF
(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)
Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation
221
dmmGF 2
21dqqkF
Differences 1 Gravitational Force is based on MASS
Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force
The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively
small forceldquokrdquo is a huge number therefore electric force is a
relatively large force
Both laws are INVERSE SQUARE LAWSldquoThe Force varies with the inverse of the
distance squaredrdquoAt twice the distance d2 = 22 in denominator = frac14 the ForceAt three times the distance 32 in denominator= 19 the ForceAt half the distance (12)2 in denominator= 4 times the ForceNow if one CHARGE q doubleshellip The Force
doubles since they are directly related
221
dqqkF
Get a calculator and letrsquos practice onehellip
What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)USE THE EXPONENT BUTTONF = 9E9 32E-3 248E-6 divide 24E-3 2 F = 124000000 N
or for Quest 124E8or 124e8
221
dqqkF
RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge
+-
+
Get a clicker and calculator Log in and get ready to answer some questions
1 Electric Charge is measured inA AmpsB VoltsC CoulombsD Farads
2 Opposite chargesA AttractB RepelC May attract or repel depending on their
relative sizeD Neither attract nor repel
3 Objects with a neutral charge are A Attracted only by objects with a net
positive chargeB Attracted only by objects with a net
negative chargeC Not attracted by any kind of chargeD Attracted by objects with either positive or
negative charge
The charge of one electron = - 16 x 10-19 C
4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)
5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of
A 3B 6C 9D 13E 16F 19
221
dqqkF
- Static Electricity ldquoElectrostaticsrdquo
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Robert Millikan
- Slide 8
- Slide 9
- Slide 10
- Lightning
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Get a calculator and letrsquos practice onehellip
- RememberhellipForce is a VECTOR- it always points in a specific dir
- Slide 23
- Get a clicker and calculator Log in and get ready to answer s
- Slide 25
- Slide 26
- The charge of one electron = - 16 x 10-19 C
- Slide 28
-
ndash Water insulator or conductorbull PURE water does NOT conduct electricitybull Impurities or ions in water can allow conductionbull The purer the water the lower the conductivitybull (the conduction of electricity is called
ELECTROLYTIC behavior- )ndash Air insulator or conductor
bull Usually an insulator thankfullybull When strong forces are present electronrsquos can be
stripped from air molecules creating ionsbull example lightning
LightningAn electrical discharge between the clouds
and the ground or between two clouds
As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING
The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)
We call that THUNDER
How much electrical charge is flowing through a lightning bolt
Typically around 10 Coulombs of chargeHow many electrons each with a negative
charge of 16 x 10-19 C does it take to have 10 C of charge
10 C 16 x 10-19 C =625 x 1019 electrons
How many electrons are flowing in a 12 C lightning bolt
75 x 1019 electrons
The Earth is able to absorb much electrical charge
Touching a charged object to the Earth in order to discharge it is called
GROUNDING
bull Methods to electrically charge an object
ndash Conduction bull Direct contact will transfer
electrons such as touching your car door in the winter
bull Friction rubbing your feet against carpet hair against a balloon
ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object
near but not in contact with a neutral object
bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object
bull If provided a pathway the separated electrons will leave
bull The object is now positively charged
bull Electrostatics devicesndash Electroscope the
separation of metal leaves indicates the presence of static charge
ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome
ndash Electrophorus a device used to transfer electric charge
Coulombrsquos Lawndash Calculates the magnitude
of the electric force between two charges
ndash Each charge experiences equal but opposite forces
k is a constant k = 9 x 109 Nm2C2
221
dqqkF
(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)
Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation
221
dmmGF 2
21dqqkF
Differences 1 Gravitational Force is based on MASS
Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force
The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively
small forceldquokrdquo is a huge number therefore electric force is a
relatively large force
Both laws are INVERSE SQUARE LAWSldquoThe Force varies with the inverse of the
distance squaredrdquoAt twice the distance d2 = 22 in denominator = frac14 the ForceAt three times the distance 32 in denominator= 19 the ForceAt half the distance (12)2 in denominator= 4 times the ForceNow if one CHARGE q doubleshellip The Force
doubles since they are directly related
221
dqqkF
Get a calculator and letrsquos practice onehellip
What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)USE THE EXPONENT BUTTONF = 9E9 32E-3 248E-6 divide 24E-3 2 F = 124000000 N
or for Quest 124E8or 124e8
221
dqqkF
RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge
+-
+
Get a clicker and calculator Log in and get ready to answer some questions
1 Electric Charge is measured inA AmpsB VoltsC CoulombsD Farads
2 Opposite chargesA AttractB RepelC May attract or repel depending on their
relative sizeD Neither attract nor repel
3 Objects with a neutral charge are A Attracted only by objects with a net
positive chargeB Attracted only by objects with a net
negative chargeC Not attracted by any kind of chargeD Attracted by objects with either positive or
negative charge
The charge of one electron = - 16 x 10-19 C
4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)
5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of
A 3B 6C 9D 13E 16F 19
221
dqqkF
- Static Electricity ldquoElectrostaticsrdquo
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Robert Millikan
- Slide 8
- Slide 9
- Slide 10
- Lightning
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Get a calculator and letrsquos practice onehellip
- RememberhellipForce is a VECTOR- it always points in a specific dir
- Slide 23
- Get a clicker and calculator Log in and get ready to answer s
- Slide 25
- Slide 26
- The charge of one electron = - 16 x 10-19 C
- Slide 28
-
LightningAn electrical discharge between the clouds
and the ground or between two clouds
As the electrons flow through the ionized air they generate so much heat that a PLASMA is produced We see that plasma and call it LIGHTNING
The air around the lightning expands so rapidly from the heat that it creates a strong pressure wave of air molecules (thatrsquos sound)
We call that THUNDER
How much electrical charge is flowing through a lightning bolt
Typically around 10 Coulombs of chargeHow many electrons each with a negative
charge of 16 x 10-19 C does it take to have 10 C of charge
10 C 16 x 10-19 C =625 x 1019 electrons
How many electrons are flowing in a 12 C lightning bolt
75 x 1019 electrons
The Earth is able to absorb much electrical charge
Touching a charged object to the Earth in order to discharge it is called
GROUNDING
bull Methods to electrically charge an object
ndash Conduction bull Direct contact will transfer
electrons such as touching your car door in the winter
bull Friction rubbing your feet against carpet hair against a balloon
ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object
near but not in contact with a neutral object
bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object
bull If provided a pathway the separated electrons will leave
bull The object is now positively charged
bull Electrostatics devicesndash Electroscope the
separation of metal leaves indicates the presence of static charge
ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome
ndash Electrophorus a device used to transfer electric charge
Coulombrsquos Lawndash Calculates the magnitude
of the electric force between two charges
ndash Each charge experiences equal but opposite forces
k is a constant k = 9 x 109 Nm2C2
221
dqqkF
(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)
Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation
221
dmmGF 2
21dqqkF
Differences 1 Gravitational Force is based on MASS
Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force
The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively
small forceldquokrdquo is a huge number therefore electric force is a
relatively large force
Both laws are INVERSE SQUARE LAWSldquoThe Force varies with the inverse of the
distance squaredrdquoAt twice the distance d2 = 22 in denominator = frac14 the ForceAt three times the distance 32 in denominator= 19 the ForceAt half the distance (12)2 in denominator= 4 times the ForceNow if one CHARGE q doubleshellip The Force
doubles since they are directly related
221
dqqkF
Get a calculator and letrsquos practice onehellip
What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)USE THE EXPONENT BUTTONF = 9E9 32E-3 248E-6 divide 24E-3 2 F = 124000000 N
or for Quest 124E8or 124e8
221
dqqkF
RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge
+-
+
Get a clicker and calculator Log in and get ready to answer some questions
1 Electric Charge is measured inA AmpsB VoltsC CoulombsD Farads
2 Opposite chargesA AttractB RepelC May attract or repel depending on their
relative sizeD Neither attract nor repel
3 Objects with a neutral charge are A Attracted only by objects with a net
positive chargeB Attracted only by objects with a net
negative chargeC Not attracted by any kind of chargeD Attracted by objects with either positive or
negative charge
The charge of one electron = - 16 x 10-19 C
4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)
5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of
A 3B 6C 9D 13E 16F 19
221
dqqkF
- Static Electricity ldquoElectrostaticsrdquo
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Robert Millikan
- Slide 8
- Slide 9
- Slide 10
- Lightning
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Get a calculator and letrsquos practice onehellip
- RememberhellipForce is a VECTOR- it always points in a specific dir
- Slide 23
- Get a clicker and calculator Log in and get ready to answer s
- Slide 25
- Slide 26
- The charge of one electron = - 16 x 10-19 C
- Slide 28
-
How much electrical charge is flowing through a lightning bolt
Typically around 10 Coulombs of chargeHow many electrons each with a negative
charge of 16 x 10-19 C does it take to have 10 C of charge
10 C 16 x 10-19 C =625 x 1019 electrons
How many electrons are flowing in a 12 C lightning bolt
75 x 1019 electrons
The Earth is able to absorb much electrical charge
Touching a charged object to the Earth in order to discharge it is called
GROUNDING
bull Methods to electrically charge an object
ndash Conduction bull Direct contact will transfer
electrons such as touching your car door in the winter
bull Friction rubbing your feet against carpet hair against a balloon
ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object
near but not in contact with a neutral object
bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object
bull If provided a pathway the separated electrons will leave
bull The object is now positively charged
bull Electrostatics devicesndash Electroscope the
separation of metal leaves indicates the presence of static charge
ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome
ndash Electrophorus a device used to transfer electric charge
Coulombrsquos Lawndash Calculates the magnitude
of the electric force between two charges
ndash Each charge experiences equal but opposite forces
k is a constant k = 9 x 109 Nm2C2
221
dqqkF
(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)
Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation
221
dmmGF 2
21dqqkF
Differences 1 Gravitational Force is based on MASS
Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force
The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively
small forceldquokrdquo is a huge number therefore electric force is a
relatively large force
Both laws are INVERSE SQUARE LAWSldquoThe Force varies with the inverse of the
distance squaredrdquoAt twice the distance d2 = 22 in denominator = frac14 the ForceAt three times the distance 32 in denominator= 19 the ForceAt half the distance (12)2 in denominator= 4 times the ForceNow if one CHARGE q doubleshellip The Force
doubles since they are directly related
221
dqqkF
Get a calculator and letrsquos practice onehellip
What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)USE THE EXPONENT BUTTONF = 9E9 32E-3 248E-6 divide 24E-3 2 F = 124000000 N
or for Quest 124E8or 124e8
221
dqqkF
RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge
+-
+
Get a clicker and calculator Log in and get ready to answer some questions
1 Electric Charge is measured inA AmpsB VoltsC CoulombsD Farads
2 Opposite chargesA AttractB RepelC May attract or repel depending on their
relative sizeD Neither attract nor repel
3 Objects with a neutral charge are A Attracted only by objects with a net
positive chargeB Attracted only by objects with a net
negative chargeC Not attracted by any kind of chargeD Attracted by objects with either positive or
negative charge
The charge of one electron = - 16 x 10-19 C
4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)
5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of
A 3B 6C 9D 13E 16F 19
221
dqqkF
- Static Electricity ldquoElectrostaticsrdquo
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Robert Millikan
- Slide 8
- Slide 9
- Slide 10
- Lightning
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Get a calculator and letrsquos practice onehellip
- RememberhellipForce is a VECTOR- it always points in a specific dir
- Slide 23
- Get a clicker and calculator Log in and get ready to answer s
- Slide 25
- Slide 26
- The charge of one electron = - 16 x 10-19 C
- Slide 28
-
The Earth is able to absorb much electrical charge
Touching a charged object to the Earth in order to discharge it is called
GROUNDING
bull Methods to electrically charge an object
ndash Conduction bull Direct contact will transfer
electrons such as touching your car door in the winter
bull Friction rubbing your feet against carpet hair against a balloon
ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object
near but not in contact with a neutral object
bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object
bull If provided a pathway the separated electrons will leave
bull The object is now positively charged
bull Electrostatics devicesndash Electroscope the
separation of metal leaves indicates the presence of static charge
ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome
ndash Electrophorus a device used to transfer electric charge
Coulombrsquos Lawndash Calculates the magnitude
of the electric force between two charges
ndash Each charge experiences equal but opposite forces
k is a constant k = 9 x 109 Nm2C2
221
dqqkF
(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)
Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation
221
dmmGF 2
21dqqkF
Differences 1 Gravitational Force is based on MASS
Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force
The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively
small forceldquokrdquo is a huge number therefore electric force is a
relatively large force
Both laws are INVERSE SQUARE LAWSldquoThe Force varies with the inverse of the
distance squaredrdquoAt twice the distance d2 = 22 in denominator = frac14 the ForceAt three times the distance 32 in denominator= 19 the ForceAt half the distance (12)2 in denominator= 4 times the ForceNow if one CHARGE q doubleshellip The Force
doubles since they are directly related
221
dqqkF
Get a calculator and letrsquos practice onehellip
What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)USE THE EXPONENT BUTTONF = 9E9 32E-3 248E-6 divide 24E-3 2 F = 124000000 N
or for Quest 124E8or 124e8
221
dqqkF
RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge
+-
+
Get a clicker and calculator Log in and get ready to answer some questions
1 Electric Charge is measured inA AmpsB VoltsC CoulombsD Farads
2 Opposite chargesA AttractB RepelC May attract or repel depending on their
relative sizeD Neither attract nor repel
3 Objects with a neutral charge are A Attracted only by objects with a net
positive chargeB Attracted only by objects with a net
negative chargeC Not attracted by any kind of chargeD Attracted by objects with either positive or
negative charge
The charge of one electron = - 16 x 10-19 C
4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)
5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of
A 3B 6C 9D 13E 16F 19
221
dqqkF
- Static Electricity ldquoElectrostaticsrdquo
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Robert Millikan
- Slide 8
- Slide 9
- Slide 10
- Lightning
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Get a calculator and letrsquos practice onehellip
- RememberhellipForce is a VECTOR- it always points in a specific dir
- Slide 23
- Get a clicker and calculator Log in and get ready to answer s
- Slide 25
- Slide 26
- The charge of one electron = - 16 x 10-19 C
- Slide 28
-
bull Methods to electrically charge an object
ndash Conduction bull Direct contact will transfer
electrons such as touching your car door in the winter
bull Friction rubbing your feet against carpet hair against a balloon
ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object
near but not in contact with a neutral object
bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object
bull If provided a pathway the separated electrons will leave
bull The object is now positively charged
bull Electrostatics devicesndash Electroscope the
separation of metal leaves indicates the presence of static charge
ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome
ndash Electrophorus a device used to transfer electric charge
Coulombrsquos Lawndash Calculates the magnitude
of the electric force between two charges
ndash Each charge experiences equal but opposite forces
k is a constant k = 9 x 109 Nm2C2
221
dqqkF
(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)
Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation
221
dmmGF 2
21dqqkF
Differences 1 Gravitational Force is based on MASS
Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force
The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively
small forceldquokrdquo is a huge number therefore electric force is a
relatively large force
Both laws are INVERSE SQUARE LAWSldquoThe Force varies with the inverse of the
distance squaredrdquoAt twice the distance d2 = 22 in denominator = frac14 the ForceAt three times the distance 32 in denominator= 19 the ForceAt half the distance (12)2 in denominator= 4 times the ForceNow if one CHARGE q doubleshellip The Force
doubles since they are directly related
221
dqqkF
Get a calculator and letrsquos practice onehellip
What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)USE THE EXPONENT BUTTONF = 9E9 32E-3 248E-6 divide 24E-3 2 F = 124000000 N
or for Quest 124E8or 124e8
221
dqqkF
RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge
+-
+
Get a clicker and calculator Log in and get ready to answer some questions
1 Electric Charge is measured inA AmpsB VoltsC CoulombsD Farads
2 Opposite chargesA AttractB RepelC May attract or repel depending on their
relative sizeD Neither attract nor repel
3 Objects with a neutral charge are A Attracted only by objects with a net
positive chargeB Attracted only by objects with a net
negative chargeC Not attracted by any kind of chargeD Attracted by objects with either positive or
negative charge
The charge of one electron = - 16 x 10-19 C
4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)
5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of
A 3B 6C 9D 13E 16F 19
221
dqqkF
- Static Electricity ldquoElectrostaticsrdquo
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Robert Millikan
- Slide 8
- Slide 9
- Slide 10
- Lightning
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Get a calculator and letrsquos practice onehellip
- RememberhellipForce is a VECTOR- it always points in a specific dir
- Slide 23
- Get a clicker and calculator Log in and get ready to answer s
- Slide 25
- Slide 26
- The charge of one electron = - 16 x 10-19 C
- Slide 28
-
ndash Induction no direct contactbull Start with a neutral object Then bring an electrically charged object
near but not in contact with a neutral object
bull The charges in the neutral object will be ldquoinducedrdquo to separate to get closer or farther from the charged object
bull If provided a pathway the separated electrons will leave
bull The object is now positively charged
bull Electrostatics devicesndash Electroscope the
separation of metal leaves indicates the presence of static charge
ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome
ndash Electrophorus a device used to transfer electric charge
Coulombrsquos Lawndash Calculates the magnitude
of the electric force between two charges
ndash Each charge experiences equal but opposite forces
k is a constant k = 9 x 109 Nm2C2
221
dqqkF
(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)
Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation
221
dmmGF 2
21dqqkF
Differences 1 Gravitational Force is based on MASS
Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force
The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively
small forceldquokrdquo is a huge number therefore electric force is a
relatively large force
Both laws are INVERSE SQUARE LAWSldquoThe Force varies with the inverse of the
distance squaredrdquoAt twice the distance d2 = 22 in denominator = frac14 the ForceAt three times the distance 32 in denominator= 19 the ForceAt half the distance (12)2 in denominator= 4 times the ForceNow if one CHARGE q doubleshellip The Force
doubles since they are directly related
221
dqqkF
Get a calculator and letrsquos practice onehellip
What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)USE THE EXPONENT BUTTONF = 9E9 32E-3 248E-6 divide 24E-3 2 F = 124000000 N
or for Quest 124E8or 124e8
221
dqqkF
RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge
+-
+
Get a clicker and calculator Log in and get ready to answer some questions
1 Electric Charge is measured inA AmpsB VoltsC CoulombsD Farads
2 Opposite chargesA AttractB RepelC May attract or repel depending on their
relative sizeD Neither attract nor repel
3 Objects with a neutral charge are A Attracted only by objects with a net
positive chargeB Attracted only by objects with a net
negative chargeC Not attracted by any kind of chargeD Attracted by objects with either positive or
negative charge
The charge of one electron = - 16 x 10-19 C
4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)
5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of
A 3B 6C 9D 13E 16F 19
221
dqqkF
- Static Electricity ldquoElectrostaticsrdquo
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Robert Millikan
- Slide 8
- Slide 9
- Slide 10
- Lightning
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Get a calculator and letrsquos practice onehellip
- RememberhellipForce is a VECTOR- it always points in a specific dir
- Slide 23
- Get a clicker and calculator Log in and get ready to answer s
- Slide 25
- Slide 26
- The charge of one electron = - 16 x 10-19 C
- Slide 28
-
bull Electrostatics devicesndash Electroscope the
separation of metal leaves indicates the presence of static charge
ndash Van de Graaff generator charge is delivered by a rubber belt to a metal dome
ndash Electrophorus a device used to transfer electric charge
Coulombrsquos Lawndash Calculates the magnitude
of the electric force between two charges
ndash Each charge experiences equal but opposite forces
k is a constant k = 9 x 109 Nm2C2
221
dqqkF
(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)
Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation
221
dmmGF 2
21dqqkF
Differences 1 Gravitational Force is based on MASS
Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force
The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively
small forceldquokrdquo is a huge number therefore electric force is a
relatively large force
Both laws are INVERSE SQUARE LAWSldquoThe Force varies with the inverse of the
distance squaredrdquoAt twice the distance d2 = 22 in denominator = frac14 the ForceAt three times the distance 32 in denominator= 19 the ForceAt half the distance (12)2 in denominator= 4 times the ForceNow if one CHARGE q doubleshellip The Force
doubles since they are directly related
221
dqqkF
Get a calculator and letrsquos practice onehellip
What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)USE THE EXPONENT BUTTONF = 9E9 32E-3 248E-6 divide 24E-3 2 F = 124000000 N
or for Quest 124E8or 124e8
221
dqqkF
RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge
+-
+
Get a clicker and calculator Log in and get ready to answer some questions
1 Electric Charge is measured inA AmpsB VoltsC CoulombsD Farads
2 Opposite chargesA AttractB RepelC May attract or repel depending on their
relative sizeD Neither attract nor repel
3 Objects with a neutral charge are A Attracted only by objects with a net
positive chargeB Attracted only by objects with a net
negative chargeC Not attracted by any kind of chargeD Attracted by objects with either positive or
negative charge
The charge of one electron = - 16 x 10-19 C
4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)
5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of
A 3B 6C 9D 13E 16F 19
221
dqqkF
- Static Electricity ldquoElectrostaticsrdquo
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Robert Millikan
- Slide 8
- Slide 9
- Slide 10
- Lightning
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Get a calculator and letrsquos practice onehellip
- RememberhellipForce is a VECTOR- it always points in a specific dir
- Slide 23
- Get a clicker and calculator Log in and get ready to answer s
- Slide 25
- Slide 26
- The charge of one electron = - 16 x 10-19 C
- Slide 28
-
Coulombrsquos Lawndash Calculates the magnitude
of the electric force between two charges
ndash Each charge experiences equal but opposite forces
k is a constant k = 9 x 109 Nm2C2
221
dqqkF
(Since we are interested in the MAGNITUDE of the force do not include the signs of negative charges)
Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation
221
dmmGF 2
21dqqkF
Differences 1 Gravitational Force is based on MASS
Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force
The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively
small forceldquokrdquo is a huge number therefore electric force is a
relatively large force
Both laws are INVERSE SQUARE LAWSldquoThe Force varies with the inverse of the
distance squaredrdquoAt twice the distance d2 = 22 in denominator = frac14 the ForceAt three times the distance 32 in denominator= 19 the ForceAt half the distance (12)2 in denominator= 4 times the ForceNow if one CHARGE q doubleshellip The Force
doubles since they are directly related
221
dqqkF
Get a calculator and letrsquos practice onehellip
What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)USE THE EXPONENT BUTTONF = 9E9 32E-3 248E-6 divide 24E-3 2 F = 124000000 N
or for Quest 124E8or 124e8
221
dqqkF
RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge
+-
+
Get a clicker and calculator Log in and get ready to answer some questions
1 Electric Charge is measured inA AmpsB VoltsC CoulombsD Farads
2 Opposite chargesA AttractB RepelC May attract or repel depending on their
relative sizeD Neither attract nor repel
3 Objects with a neutral charge are A Attracted only by objects with a net
positive chargeB Attracted only by objects with a net
negative chargeC Not attracted by any kind of chargeD Attracted by objects with either positive or
negative charge
The charge of one electron = - 16 x 10-19 C
4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)
5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of
A 3B 6C 9D 13E 16F 19
221
dqqkF
- Static Electricity ldquoElectrostaticsrdquo
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Robert Millikan
- Slide 8
- Slide 9
- Slide 10
- Lightning
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Get a calculator and letrsquos practice onehellip
- RememberhellipForce is a VECTOR- it always points in a specific dir
- Slide 23
- Get a clicker and calculator Log in and get ready to answer s
- Slide 25
- Slide 26
- The charge of one electron = - 16 x 10-19 C
- Slide 28
-
Coulombrsquos Law looks VERY similar to Newtonrsquos Universal Law of Gravitation
221
dmmGF 2
21dqqkF
Differences 1 Gravitational Force is based on MASS
Coulombrsquos law is based on CHARGE2 Gravity is ALWAYS an attractive force
The Electric Force can attract and repel3 ldquoGrdquo is a tiny number therefore gravity force is a relatively
small forceldquokrdquo is a huge number therefore electric force is a
relatively large force
Both laws are INVERSE SQUARE LAWSldquoThe Force varies with the inverse of the
distance squaredrdquoAt twice the distance d2 = 22 in denominator = frac14 the ForceAt three times the distance 32 in denominator= 19 the ForceAt half the distance (12)2 in denominator= 4 times the ForceNow if one CHARGE q doubleshellip The Force
doubles since they are directly related
221
dqqkF
Get a calculator and letrsquos practice onehellip
What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)USE THE EXPONENT BUTTONF = 9E9 32E-3 248E-6 divide 24E-3 2 F = 124000000 N
or for Quest 124E8or 124e8
221
dqqkF
RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge
+-
+
Get a clicker and calculator Log in and get ready to answer some questions
1 Electric Charge is measured inA AmpsB VoltsC CoulombsD Farads
2 Opposite chargesA AttractB RepelC May attract or repel depending on their
relative sizeD Neither attract nor repel
3 Objects with a neutral charge are A Attracted only by objects with a net
positive chargeB Attracted only by objects with a net
negative chargeC Not attracted by any kind of chargeD Attracted by objects with either positive or
negative charge
The charge of one electron = - 16 x 10-19 C
4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)
5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of
A 3B 6C 9D 13E 16F 19
221
dqqkF
- Static Electricity ldquoElectrostaticsrdquo
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Robert Millikan
- Slide 8
- Slide 9
- Slide 10
- Lightning
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Get a calculator and letrsquos practice onehellip
- RememberhellipForce is a VECTOR- it always points in a specific dir
- Slide 23
- Get a clicker and calculator Log in and get ready to answer s
- Slide 25
- Slide 26
- The charge of one electron = - 16 x 10-19 C
- Slide 28
-
Both laws are INVERSE SQUARE LAWSldquoThe Force varies with the inverse of the
distance squaredrdquoAt twice the distance d2 = 22 in denominator = frac14 the ForceAt three times the distance 32 in denominator= 19 the ForceAt half the distance (12)2 in denominator= 4 times the ForceNow if one CHARGE q doubleshellip The Force
doubles since they are directly related
221
dqqkF
Get a calculator and letrsquos practice onehellip
What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)USE THE EXPONENT BUTTONF = 9E9 32E-3 248E-6 divide 24E-3 2 F = 124000000 N
or for Quest 124E8or 124e8
221
dqqkF
RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge
+-
+
Get a clicker and calculator Log in and get ready to answer some questions
1 Electric Charge is measured inA AmpsB VoltsC CoulombsD Farads
2 Opposite chargesA AttractB RepelC May attract or repel depending on their
relative sizeD Neither attract nor repel
3 Objects with a neutral charge are A Attracted only by objects with a net
positive chargeB Attracted only by objects with a net
negative chargeC Not attracted by any kind of chargeD Attracted by objects with either positive or
negative charge
The charge of one electron = - 16 x 10-19 C
4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)
5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of
A 3B 6C 9D 13E 16F 19
221
dqqkF
- Static Electricity ldquoElectrostaticsrdquo
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Robert Millikan
- Slide 8
- Slide 9
- Slide 10
- Lightning
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Get a calculator and letrsquos practice onehellip
- RememberhellipForce is a VECTOR- it always points in a specific dir
- Slide 23
- Get a clicker and calculator Log in and get ready to answer s
- Slide 25
- Slide 26
- The charge of one electron = - 16 x 10-19 C
- Slide 28
-
Get a calculator and letrsquos practice onehellip
What is the magnitude of the electrostatic force between two charges q1 = 32 mC and q2 = -248 mC separated by a distance of 24 mm (milli = 10-3 micro = 10-6)USE THE EXPONENT BUTTONF = 9E9 32E-3 248E-6 divide 24E-3 2 F = 124000000 N
or for Quest 124E8or 124e8
221
dqqkF
RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge
+-
+
Get a clicker and calculator Log in and get ready to answer some questions
1 Electric Charge is measured inA AmpsB VoltsC CoulombsD Farads
2 Opposite chargesA AttractB RepelC May attract or repel depending on their
relative sizeD Neither attract nor repel
3 Objects with a neutral charge are A Attracted only by objects with a net
positive chargeB Attracted only by objects with a net
negative chargeC Not attracted by any kind of chargeD Attracted by objects with either positive or
negative charge
The charge of one electron = - 16 x 10-19 C
4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)
5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of
A 3B 6C 9D 13E 16F 19
221
dqqkF
- Static Electricity ldquoElectrostaticsrdquo
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Robert Millikan
- Slide 8
- Slide 9
- Slide 10
- Lightning
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Get a calculator and letrsquos practice onehellip
- RememberhellipForce is a VECTOR- it always points in a specific dir
- Slide 23
- Get a clicker and calculator Log in and get ready to answer s
- Slide 25
- Slide 26
- The charge of one electron = - 16 x 10-19 C
- Slide 28
-
RememberhellipForce is a VECTOR- it always points in a specific direction If more than two charges are present we must find the VECTOR sum of the forces acting on an individual charge
+-
+
Get a clicker and calculator Log in and get ready to answer some questions
1 Electric Charge is measured inA AmpsB VoltsC CoulombsD Farads
2 Opposite chargesA AttractB RepelC May attract or repel depending on their
relative sizeD Neither attract nor repel
3 Objects with a neutral charge are A Attracted only by objects with a net
positive chargeB Attracted only by objects with a net
negative chargeC Not attracted by any kind of chargeD Attracted by objects with either positive or
negative charge
The charge of one electron = - 16 x 10-19 C
4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)
5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of
A 3B 6C 9D 13E 16F 19
221
dqqkF
- Static Electricity ldquoElectrostaticsrdquo
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Robert Millikan
- Slide 8
- Slide 9
- Slide 10
- Lightning
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Get a calculator and letrsquos practice onehellip
- RememberhellipForce is a VECTOR- it always points in a specific dir
- Slide 23
- Get a clicker and calculator Log in and get ready to answer s
- Slide 25
- Slide 26
- The charge of one electron = - 16 x 10-19 C
- Slide 28
-
Get a clicker and calculator Log in and get ready to answer some questions
1 Electric Charge is measured inA AmpsB VoltsC CoulombsD Farads
2 Opposite chargesA AttractB RepelC May attract or repel depending on their
relative sizeD Neither attract nor repel
3 Objects with a neutral charge are A Attracted only by objects with a net
positive chargeB Attracted only by objects with a net
negative chargeC Not attracted by any kind of chargeD Attracted by objects with either positive or
negative charge
The charge of one electron = - 16 x 10-19 C
4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)
5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of
A 3B 6C 9D 13E 16F 19
221
dqqkF
- Static Electricity ldquoElectrostaticsrdquo
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Robert Millikan
- Slide 8
- Slide 9
- Slide 10
- Lightning
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Get a calculator and letrsquos practice onehellip
- RememberhellipForce is a VECTOR- it always points in a specific dir
- Slide 23
- Get a clicker and calculator Log in and get ready to answer s
- Slide 25
- Slide 26
- The charge of one electron = - 16 x 10-19 C
- Slide 28
-
2 Opposite chargesA AttractB RepelC May attract or repel depending on their
relative sizeD Neither attract nor repel
3 Objects with a neutral charge are A Attracted only by objects with a net
positive chargeB Attracted only by objects with a net
negative chargeC Not attracted by any kind of chargeD Attracted by objects with either positive or
negative charge
The charge of one electron = - 16 x 10-19 C
4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)
5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of
A 3B 6C 9D 13E 16F 19
221
dqqkF
- Static Electricity ldquoElectrostaticsrdquo
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Robert Millikan
- Slide 8
- Slide 9
- Slide 10
- Lightning
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Get a calculator and letrsquos practice onehellip
- RememberhellipForce is a VECTOR- it always points in a specific dir
- Slide 23
- Get a clicker and calculator Log in and get ready to answer s
- Slide 25
- Slide 26
- The charge of one electron = - 16 x 10-19 C
- Slide 28
-
3 Objects with a neutral charge are A Attracted only by objects with a net
positive chargeB Attracted only by objects with a net
negative chargeC Not attracted by any kind of chargeD Attracted by objects with either positive or
negative charge
The charge of one electron = - 16 x 10-19 C
4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)
5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of
A 3B 6C 9D 13E 16F 19
221
dqqkF
- Static Electricity ldquoElectrostaticsrdquo
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Robert Millikan
- Slide 8
- Slide 9
- Slide 10
- Lightning
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Get a calculator and letrsquos practice onehellip
- RememberhellipForce is a VECTOR- it always points in a specific dir
- Slide 23
- Get a clicker and calculator Log in and get ready to answer s
- Slide 25
- Slide 26
- The charge of one electron = - 16 x 10-19 C
- Slide 28
-
The charge of one electron = - 16 x 10-19 C
4 How much excess charge is present in an object that has 3 x 1018 more electrons than protons (Use correct sign)
5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of
A 3B 6C 9D 13E 16F 19
221
dqqkF
- Static Electricity ldquoElectrostaticsrdquo
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Robert Millikan
- Slide 8
- Slide 9
- Slide 10
- Lightning
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Get a calculator and letrsquos practice onehellip
- RememberhellipForce is a VECTOR- it always points in a specific dir
- Slide 23
- Get a clicker and calculator Log in and get ready to answer s
- Slide 25
- Slide 26
- The charge of one electron = - 16 x 10-19 C
- Slide 28
-
5 If the distance between two charges tripled the magnitude of the electrostatic force between them would change by a factor of
A 3B 6C 9D 13E 16F 19
221
dqqkF
- Static Electricity ldquoElectrostaticsrdquo
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Robert Millikan
- Slide 8
- Slide 9
- Slide 10
- Lightning
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Get a calculator and letrsquos practice onehellip
- RememberhellipForce is a VECTOR- it always points in a specific dir
- Slide 23
- Get a clicker and calculator Log in and get ready to answer s
- Slide 25
- Slide 26
- The charge of one electron = - 16 x 10-19 C
- Slide 28
-