1. What is Physics?

2. What is Physics? Physics is
the scientific study of the physical world: matter, energy, motion, and force.
The study of the fundamental laws of nature, which, simply put, are the laws that underlie all physical phenomena in the universe.
From a Greek term meaning "the science of nature."

3. What is Physics? Continued
Physics is everywhere, in fact most people know more about it than they think they do
When you buy ice cream you know that you need to put it in the freezer. Why? Because it would melt otherwise.
Any problem that deals with temperature, size, motion, position, shape, or color involves physics.
We have remarkably found that these laws can be expressed in terms of mathematical equations.

4. Areas within Physics Thermodynamics Electromagnetism Name Subjects
Examples
Mechanics
Motion and its causes, interactions between objects
Falling objects, friction, weight, spinning objects
Thermodynamics
Heat and Temperature
Melting and freezing processes, engines, refrigerators
Vibrations and Wave Phenomena
Specific types of repetitive motions
Springs, pendulums, sound
Optics
Light
Mirrors, lenses, color, astronomy
Electromagnetism
Electricity, magnetism, and light
Electrical charge, circuitry, permanent magnets, electromagnets
Relativity
Particles moving at any speed, including very high speeds
Particle collisions, particle accelerators, nuclear energy
Quantum mechanics
Behavior of submicroscopic particles
The atom and its parts

5. This is Physics!!

6. SI Units Quantity Name SI Abbreviation Length Meter m Mass Kilogram kg
Time
Second s
Electric current
Ampere A

7. SI Prefixes
Prefixes are used to change the size of the base unit. Used instead of writing a lot of zeroes.

8. Conversion Factors Conversion factor
A ratio of equivalent measurements.
Useful in solving problems in which a given measurement must be expressed in some other unit of measurement.

9. Dimensional Analysis Dimensional analysis
A way to analyze and solve problems using the units of the measurements.

11. Converting Between Units

12. Multistep Problems

13. Converting Complex Units

14. Practice Problems
A minivan sells for 33,200 dollars. Express the price for a minivan in kilodollars and Megadollars?
A Typical E.coli bacterium is about 5 micrometers in length.Give the length in millimeters and kilometers.
How many seconds are in a leap year?
Convert the speed 5.30 m/s to km/h.

15. Scientific Notation
Scientist often deal with very large or very small numbers. These numbers can be expressed in powers of 10
Numbers take the form of
M X 10n
Where M = a number 1 – 10
And n = the number of decimal places moved

16. Conversions using Scientific Notation with large numbers
Ex 1
Convert 1,500,000 to scientific notation.
First move the decimal place so that there is only one digit to its left
1.5
How many spaces did we move them? 6
So we write it as
1.5 x 106

17. Conversions using Scientific Notation with small numbers
Ex 1
Convert to scientific notation
First move the decimal
2.5
How many places did we move it? 5
So we write it as:
2.5 x 10-5 (note: since the number was less than one it is written as a negative number)

18. Sample Problems Convert the following: 5.65 x 106 4.90 x 10-4

19. Using Scientific Notation
Multiplication
The base numbers are multiplied and the exponents are added.
(4.0 x 103)(2.0 x 103) =
Division
The base numbers are divided and the exponents are subtracted.
(1.06 x 104)/(2.0 x 10-2) =
Addition or subtraction
Express all the exponents in the same power of 10. Perform the addition or subtraction, then if necessary convert to correct form of scientific notation.
7.11 x x 103 =

20. Significant Figures (Sig Figs)
All Digits 1-9 are significant
129
3 sig figs
Zeros between significant digits are significant
5,007
4 sig figs
Trailing zeros are only significant if the number contains a decimal point
100.0
100
1 sig fig
Zeros in the beginning of a number whose only function is to place the decimal points are not significant
0.0025
2 sig figs
Zeros following a decimal significant figure are significant
5 sig figs

21. Calculations using Sig Figs
When multiplying or dividing
Round to the least number of sig figs
When adding or subtracting
Round to the least amount of decimal places

22. Sample Problems 6.201 cm + 7.4 cm + .68 cm + 12.0 cm
139 cm x 2.3 cm
18.21 g  4.4 g

23. Today’s Homework Page 9 Page 20 Pages 27 – 31 1, 2 1, 2, 3,
1,2,5,7,8,11,13,16,18,19,20,21,22