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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
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!