Introduction to Physics2012-2013

Introduction to Physics2012-2013

Mrs. Tsimberg

… I’ll have you introduce

yourselves later in class to break things up a bit!

WHAT is PHYSICS?The study of matter, energy, and the interactions between them… in other words, everything!

What do you think these quotes really mean?

“Physics investigates the essential nature of the world, and biology describes a local bump. Psychology … describes a bump on a bump.”

Willard Van Orman Quine, American philosopher (1908 – 2000)

Branches of Physics Mechanics –matter, motion, forces, and

energy. Only describes objects bigger than atoms and slower than light.

Thermodynamics –heat and temperature

Electromagnetism - electricity, magnetism, and light

Relativity –particles moving at any speed, including very high speeds

Quantum Mechanics – behavior of submicroscopic particles

Side Note Theory of Classical Mechanics worked

perfectly for more than 100 years – and still works in most circumstances today.

Leaders of Modern physics (Einstein, Planck, Bohr, etc.) had to be open-minded when data didn’t fit with established theories

“No amount of experimentation can ever prove me right; a single experiment can prove me wrong” -- Albert Einstein

Which Branch(es)? Preparing dinner

A Soccer game

Lightning in a thunderstorm

A car accident

Lasers

Class structureMajor Objectives

Understand physical phenomena not just equation hunt

Build problem-solving abilities

Communicate scientific knowledge simply and precisely using math, graphs, pictures, and words

Assessment Daily work 20%

Labs & Projects 20%

Major Quizzes and Exams 60%

No work or unintelligible work = no credit!

Class structureRules

Respect each other’s time and learning

Bring calculator every day!

NO computers or phones (unless I specify)

Non-distracting food / drink is ok

Keys to success Practice, Practice, Practice!

Get help early & often … then try again on your own

DON’T GIVE UP … studies say the single most important factor in success at any task is GRIT

Your turn … Pick 2Introduce yourself and pick 2 things to share

with the class

Something factual Favorite hobby / activity / unusual talent

Something interesting from the summer

Something about your family

Farthest / most exotic place you’ve traveled

Something you wish Dream job (even if its not realistic)

Dream home / travel

Dream talent / experience

Unit 1: Vectors and Math skills

Statement of Inquiry: Math is a tool for explaining physical phenomenon

AOI: Human Ingenuity

Todays Objectives:

Define physics and describe the types of phenomena studied by each branch of physics

Differentiate between scientific theories, laws, and hypotheses

Express numbers in scientific notation

Recognize SI prefixes

The nature of scienceScientific ideas are developed by making and testing predictions. Nothing is ever proven in science, tests can merely support or disprove an idea.

… but some ideas have more support than others

Hypothesis –

Theory –

Law –

The nature of scienceScientific ideas are developed by making and testing predictions. Nothing is ever proven in science, tests can merely support or disprove an idea.

… but some ideas have more support than others

Hypothesis – educated guess

Theory –

Law –

The nature of scienceScientific ideas are developed by making and testing predictions. Nothing is ever proven in science, tests can merely support or disprove an idea.

… but some ideas have more support than others

Hypothesis – educated guess

Theory – one (or several related) hypotheses that have been tested and supported many many times; usually explain why something happens

Law –

The nature of scienceScientific ideas are developed by making and testing predictions. Nothing is ever proven in science, tests can merely support or disprove an idea.

… but some ideas have more support than others

Hypothesis – educated guess

Theory – one (or several related) hypotheses that have been tested and supported many many times; usually explain why something happens

Law – generalizes a body of observations with no known exceptions; only describes events does NOT explain why

The nature of scienceScientific ideas are developed by making and testing predictions. Nothing is ever proven in science, tests can merely support or disprove an idea.

… but some ideas have more support than others

Hypothesis – educated guess

Theory – one (or several related) hypotheses that have been tested and supported many many times; usually explain why something happens

Law – generalizes a body of observations with no known exceptions; only describes events does NOT explain why

Example:

Newton’s Law of Gravitation is an equation that generalizes force of attraction between 2 or more objects.

Einstein’s Theory of Relativity is a (well supported) idea about why masses exert forces on other masses

Hypothesis, theory, or law?

a. Male pupfish have bright colors to attract mates

b. Animals change over time

c. Traits that confer a reproductive advantage tend to increase in a population over time

hypothesisLaw of

Evolution

Theory of Natural Selection

How do you know?

The mass of the Earth is5972000000000000000000000000 kg

Is this a reasonable way to express this measurement?

Of course not!

Much better way:5.972 X 1027 kg

This is known as scientific notation

About Measurements…

The mass of the Earth is5972000000000000000000000000 kg

Much better way:

5.972 X 1024 kg

This is known as scientific notation

Scientific NotationTo write a number in scientific notation:

put one non-zero digit to the left of the decimal

multiple the number by a power of 10 to get correct magnitude

Examples:

0.009035 = ?

156000000 = ?

Scientific NotationTo write a number in scientific notation:

put one non-zero digit to the left of the decimal

multiple the number by a power of 10 to get correct magnitude

Examples:

0.009035 = 9.035 X 10-3

156000000 = 1.56 X 108

Scientific NotationPractice individually. If you have time, check

with tablepartner. You have 3 minutes.

1) 0.000030042) 0.04563) 10450044) 93405) 1.0053 X 10-3 (convert to expanded form!)6) 5.302 X 104 (convert to expanded form!)

Scientific NotationPractice individually. If you have time, check

with tablepartner. You have 3 minutes.

1) 0.00003004 = 3.004 X 10-5

2) 0.0456 = 4.56 X 10-2

3) 1045004 = 1.045004 X 106

4) 9340 = 9.340 X 103

5) 1.0053 X 10-3 = 0.00100536) 5.302 X 104 = 53020000

Why use Scientific Notation?

Scientific notation is useful 1) For very large or small numbers2) For showing the precision of a measurement

Example:

If I say a pumpkin is 200 lb, what do I really mean?

Maybe I mean that it is exactly 200 lbs (closer to 200 lbs than

to 201 or 199 lbs).

But, maybe I mean that is only roughly 200 lbs (closer to 200

lbs than 300 or 100 lbs)

If I say that a pumpkin is 2.00 X 102 lbs, the precision is clear … it is between 201 and 199. More on this, later!

How else might we

handle very small or large

numbers?

SI prefixes!

SI UnitsWho knows what SI units are?

The International System of Units (abbreviated SI from French: Système international d'unités) is the modern form of the metric system adopted in 1960.

Why use SI units?* universal* easy

SI PrefixesPower Prefix Abbr. Power Prefix Abbr.10-15 femto- f 10-2 centi- c

10-12 pico- p 103 kilo- k

10-9 nano- n 106 mega- M

10-6 micro- μ 109 giga- G

10-3 milli- m 1012 tera- T

!Note: These are prefixes. They go before the base unit (L, m, g, etc.)

Where does the base unit fit in?

100

Which is biggera mm or a Mm? a ng or a g?

Mmg

SI PrefixesPower Prefix Abbr. Power Prefix Abbr.

10-15 femto- f 10-2 centi- c

10-12 pico- p 103 kilo- k

10-9 nano- n 106 mega- M

10-6 micro- μ 109 giga- G

10-3 milli- m 1012 tera- T

Just for FunDiameter of atomic nucleus ≈ 5 fm!

SI PrefixesPower Prefix Abbr. Power Prefix Abbr.10-15 femto- f 10-2 centi- c

10-12 pico- p 103 kilo- k

10-9 nano- n 106 mega- M

10-6 micro- μ 109 giga- G

10-3 milli- m 1012 tera- T

Just for FunDiameter of the atom ≈ 100 pm!

SI PrefixesPower Prefix Abbr. Power Prefix Abbr.10-15 femto- f 10-2 centi- c

10-12 pico- p 103 kilo- k

10-9 nano- n 106 mega- M

10-6 micro- μ 109 giga- G

10-3 milli- m 1012 tera- T

Just for FunDiameter of a red blood cell ≈ 8 μm!

SI PrefixesPower Prefix Abbr. Power Prefix Abbr.10-15 femto- f 10-2 centi- c

10-12 pico- p 103 kilo- k

10-9 nano- n 106 mega- M

10-6 micro- μ 109 giga- G

10-3 milli- m 1012 tera- T

Just for FunDiameter of Earth ≈ 13 Mm!

SI PrefixesPower Prefix Abbr. Power Prefix Abbr.10-15 femto- f 10-2 centi- c

10-12 pico- p 103 kilo- k

10-9 nano- n 106 mega- M

10-6 micro- μ 109 giga- G

10-3 milli- m 1012 tera- T

Just for FunDiameter of sun ≈ 1.4 Gm!

SI PrefixesPower Prefix Abbr. Power Prefix Abbr.

10-15 femto- f 10-2 centi- c

10-12 pico- p 103 kilo- k

10-9 nano- n 106 mega- M

10-6 micro- μ 109 giga- G

10-3 milli- m 1012 tera- T

Just for FunDiameter of Milky Way ≈ 9500 Tm!

http://htwins.net/ Watch me!

Exit Ticket