fizzix ap – ch 16, 17, 18 honors – ch 17-20 electrostatics
DESCRIPTION
Where are we HONORS? Heat & Thermo –Done… EM –Current… Ch –Magnetism… Ch 21 & 22 –Atomic/Nuclear… Ch 23 & 25TRANSCRIPT
Fizzix Fizzix AP AP –– Ch 16, 17, 18 Ch 16, 17, 18 Honors Honors –– Ch 17-20 Ch 17-20
Electrostatics
Where are we AP?
• Heat & Thermo–Done… Ch 13-15
• EM–Current… Ch 16-22
Where are we HONORS?
• Heat & Thermo–Done…
• EM–Current… Ch 17-20–Magnetism… Ch 21 & 22–Atomic/Nuclear… Ch 23 & 25
Intro Stuff• Origin of electric charge
–Atoms (duh…)•Nucleus
–P+ & No »Even tho neither exists.
•Electron Shell–e-
Schedoole• Intro PPT
–Practice Probs• LAB
–Discovery : V=IR• Progress Reports/Grades• Whining & Bribes
Intro Stuff• e-
– e=1.60x10-19C– C?
•Coulomb–SI Unit for electric charge–Definition later – Ch19–1C is charge on 6.25 x 1018 e-
Intro Stuff• Law of Electrostatics
–Likes repel, unlikes attract–Since there is an attraction or repulsion, there MUST be a force! Hmmm. F=ma•Coulomb’s Law…
221
rqq
kFe
221
rMM
GFg
Look Familiar?
Intro Stuff• Example? Sure!
–Calculate the ratio of the gravitational and the electrostatic forces experienced by en electron orbiting the nucleus of a basic H atom. 1
1H
Intro Stuff
11
2
21929
2 211
8
5.1 10
1.6 109 10
5.1 10
8.86 10
P ee
e
e
r x mq q
F kr
x CNmF x
C x m
F x N
Intro Stuff
11
2
27 31211
2 211
47
5.1 10
1.67 10 9.11 106.67 10
5.1 10
3.90 10
p eg
g
g
r x mM M
F Grx Kg x Kg
NmF xKg x m
F x N
Intro Stuff
392 10e gF x F
Intro Stuff• Electric Field
–Area around a charge where another charge will feel a force
oqFE
Q
qo
Fe
Fe<0
Fe>0
Attracting Force
Repelling Force
Stimulating Simulations
• Forces between charges• Force Field around a single
charge• Yet another silly animation?• And another?• NO! NOT ANOTHER ONE!!!• This is just SILLY!
FizzixFizzixAP – Ch 16, 17, 18 Honors – Ch 17-20
Electric Potential
Intro Stuff• Potential Energy (‘member?)
–Ball falls from A to B
hA
hb
B
A
BAAB
BAAB
GPEGPEWmghmghW
Intro Stuff• Electical Potential Energy
–Charge ‘falls’ from A to B
dA
db
B
A
BAAB
BAAB
GPEGPEWmghmghW
++++++++++++
- - - - - - - - - - -
BAAB EPEEPEW
Intro Stuff• Electric Potential–‘V’ is the ratio EPE of a qo & the qo itself.
oqEPEV
Intro Stuff• Electric Potential DIFFERENCE
–VB=VA
o
A
o
BAB q
EPEq
EPEVVV
Intro Stuff• Electric Potential DIFFERENCE
o
A
o
BAB q
EPEq
EPEVVV
o
B
qEPE
V
Intro Stuff• Electric Potential DIFFERENCE
o
B
qEPE
V
o
AB
qW
V
Intro Stuff• Electric Potential DIFFERENCE
–Example I n t r o S t u f f• E l e c t i c a l P o t e n t i a l E n e r g y
– C h a r g e ‘ f a l l s ’ f r o m A t o B
d A
d b
B
A
BAAB
BAAB
GPEGPEWmghmghW
+ + + + + + + + + + + +
- - - - - - - - - - -
BAAB EPEEPEW
Work done by qo (2x10-6C) is 5x10-5J. Find V.
VCxJxV
qW
Vo
AB
251021056
5
Intro Stuff• Electron Volt
–Change in PE of an e- when moved through a PD of 1 Volt.
•1eV=1.60x10-19J
Intro Stuff• Capacitors
–C=q/V•Unit is Farad (F)
–C/V=F–Storage of charge–E=½CV2
•Used in MANY places…
Intro Stuff• Capacitor Examples
I n t r o S t u f f• E l e c t i c a l P o t e n t i a l E n e r g y
– C h a r g e ‘ f a l l s ’ f r o m A t o B
d A
d b
B
A
BAAB
BAAB
GPEGPEWmghmghW
+ + + + + + + + + + + +
- - - - - - - - - - -
BAAB EPEEPEW
Intro Stuff• Capacitor Examples
–Keys on keyboard
Intro Stuff• Capacitor Examples
–Electronic flash
Intro Stuff• Capacitor Examples
–Defibrillator
FizzixFizzixAP – Ch 16, 17, 18 Honors – Ch 17-20
Electric Circuits
Intro Stuff• Van de Graaff?
–Charge Pump
Intro Stuff• Van de Graaff?
–Additional Demos•Bubbles•Rice Crispies
–Volunteer???
Intro Stuff• Van de Graaff #’s?
–300,000V–<30A–10,000,000,000
•So just about everything is a ‘conductor’ to it!
Intro Stuff• Circuit?
–Power Supply–Resistance
Battery?• A thing that produces a potential difference
through a chemical reaction.– battery, electric, device that converts chemical
energy into electrical energy. • (How Stuff Works . Com)
• The act of beating or pounding. – Law. The unlawful and unwanted touching or
striking of one person by another, with the intention of bringing about a harmful or offensive contact.
• (Wiki-Idiot-Pedia.comedy)
• For example, here's what happens in one cell of a car's lead-acid battery: – The cell has one plate made of lead and another plate made of
lead dioxide, with a strong sulfuric acid electrolyte in which the plates are immersed.
– Lead combines with SO4 to create PbSO4 plus one electron. – Lead dioxide, hydrogen ions and SO4 ions, plus electrons from
the lead plate, create PbSO4 and water on the lead dioxide plate. – As the battery discharges, both plates build up PbSO4 (lead
sulfate), and water builds up in the acid. The characteristic voltage is about 2 volts per cell, so by combining six cells you get a 12-volt battery.
• A lead-acid battery has a nice feature -- the reaction is completely reversible. If you apply current to the battery at the right voltage, lead and lead dioxide form again on the plates so you can reuse the battery over and over. In a zinc-carbon battery, there is no easy way to reverse the reaction because there is no easy way to get hydrogen gas back into the electrolyte.
Intro Stuff• Electromotive Force
–emf•Maximum terminal V of battery
• Current–Flow of charge t
qI
Intro Stuff
)(Ampere
AsC
tqI
Intro Stuff• Ohm’s Law
–States linear relationship between V & R
))(( OhmAmpVoltIRV
Intro Stuff• Resistance
–Says what it means•e- has to ‘fight’ thru a wire or ‘resistor’
ALR
Intro Stuff• Resistance
–Radio Shack SCAM!
mx
mx
Au
Cu
8
8
1044.2
1072.1
lbozAu
ozlbCu
/56.754,15$/66.984$:
/24.0/87.3$:
Intro Stuff• Power
–Same as regular P, but different
IVPt
qVP
tWP
Intro Stuff• Power…
WattsRIIRIP
IVP2)(
Intro Stuff• Wiring Circuits
–Series / Parallel•Series
VVT 30
100TR
10030
;V
RV
I
So
T
TT
Intro Stuff• Wiring Circuits
–Series / Parallel•Parallel
6301
151
151
1
1111
321
T
T
T
R
R
RRR
R
Intro Stuff• Wiring Circuits
–Series / Parallel•Parallel
15 ?
AI
VRVI
1015150
80
//
////
140118
81080
R
AV
IV
R
10R
Practice Stuff• Boo-ring Book Shtuff
–Ch16 pg437 #12
Practice Stuff• Boo-ring Book Shtuff
–Ch16 pg438 #22
Practice Stuff• Boo-ring Book Shtuff
–Ch17 pg456 #7
Practice Stuff• Boo-ring Book Shtuff
–Ch17 pg456 #14
Practice Stuff• Boo-ring Book Shtuff
–Ch17 pg457 #22
Practice Stuff• Boo-ring Book Shtuff
–Ch18 pg477 #7
Practice Stuff• Boo-ring Book Shtuff
–Ch18 pg477 #12
Practice Stuff• Boo-ring Book Shtuff
–Ch18 pg478 #26
Practice Stuff• Boo-ring Book Shtuff
–Ch19 pg499 #2
Intro Stuff• Wiring Circuits
–Now, DO IT!–LABS 40, 42, 43, & 44