1. Chapter 1
The Science of Physics

2. Key Objectives Definition of Physics Areas within Physics
Scientific Method
Measurements and Units (SI)
Accuracy and Precision
Dimensional Analysis

3. Definition of Physics Physics is the study of the physical world.
Physics can be used to explain every object and phenomena around you.

4. Areas of Physics Name Subjects Mechanics Thermodynamics
Motion and its causes
Thermodynamics
Heat and Temperature
Specific types of repetitive motion
Vibrations and Waves
Optics
Light
Electromagnetism
Electricity, Magnetism, & Light
Particles moving at high speeds
Relativity
Behavior of submicroscopic particles
Quantum Mechanics

5. Accuracy v Precision Accuracy is Precision is
how close a measured value is to the true value or accepted value.
Precision is
How close each measurement is to each other measurement.
Our goal is to be both accurate and precise in our measurements.

6. Significant Figures 0 is a significant figure under certain conditions
In order to be accurate and precise with our measurements, we must pay attention to significant figures while analyzing data on the calculator.
It is used after a decimal point to show accuracy of measurement
The numbers
count as significant figures 1 2
4.2300 8 4
0 is a significant figure under certain conditions
It is trapped between other significant figures. 3 6
2804
It is used as a place holder between significant figures and the decimal. 7 5 9
0 is not a significant
figure if
430
.0222

7. Addition & Subtraction
To determine the number of significant figures you can keep when you are adding/subtracting measurements, you need to look at the least accurate measurement.
That means the number showing the least amount of digits as you move right through the number. For instance:
46.4
Shows that we are accurate to the tenths place.
9.46
Shows we are accurate to the hundredths place. +
270
Shows we are accurate to tens place!
325.86
When we add those together
330
We can only keep to the tens place.

8. Multiplication & Division
Finding how many significant figures to keep with multiplication and division is much easier than with other operations.
That is because you simply count how many significant figures are in each measurement, and keep the number of significant figures equivalent to the measurement with the least number.
46.40
Has 4 significant figures.
120.46
Has 5 significant figures x
27.1
Has 3 significant figures.
So when we multiply these together.
151,000
We can only keep 3 significant figures

9. What is the Scientific Method?
There is no single procedure that scientists follow in their work. But, there are certain steps common to all good scientific investigations. Those steps are called the scientific method.
Observation
Hypothesis
Make an educated guess for an answer to your question
Gather information that would lead to you to a question.
Conclusion
Experiment
Make a final statement based on your findings to prove your hypothesis.
Perform an experiment and collect data to support your hypothesis.

10. Units of Measurement
There are many different systems of measurements in science.
Here in the United States, we use the English system of units.
miles
pounds
Fahrenheit
Other countries, such as Canada, use the Metric system of units.
meter
gram
Celsius
Since the world cannot decide on what units to use, scientists have. We have come to a mutual agreement for a consistent system of units . . .

11. SI Units
That mutual system is called the International System of units. We abbreviate it using SI, which is short for Systeme International.
Quantity
Unit
Length
meter (m)
Mass
kilogram (kg)
Temperature
kelvin (K)
Time
second (s)
Current
ampere (A)
Energy
joule (J)
Force
newton (N)

12. Standards of Length, Mass, and Time
We all know these are used to measure certain characteristics of the phenomena around us.
Before we knew of things such as the meter, or kilogram, or second, the quantities above had no standard way of being measured.
So how did we come to designate a certain distance, or time interval, or mass as being the standards for all measurements?

13. The Meter
The meter was originally defined in France as one ten-millionth of the distance from the Equator to the North Pole.
Until 1960, the meter was defined by the distance between two lines on a specific bar of platinum-iridium alloy.
Kept in the National Institute of Standards and Technology in Sèvres, France.
In 1983 the meter took on the current definition as the distance traveled by light in a vacuum during the time interval of 1/299,792,458 second.
vlight = 299,792,458 m/s
v = fλ
λ = 1 / 299,792,458

14. The Kilogram
The kilogram is defined as the mass of a specific platinum-iridium alloy cylinder kept as the International Bureau of Weights and Measures in Sèvres, France.
Platinum-Iridium alloy is a very stable metal with no tendency to rust or be chemically altered by its environment.
It is a disadvantage to maintain a measurement that way because it is only accessible to those in the institute.
So any other kilogram measurement is accepted to be so.

15. The Second
Before 1960, the time standard was defined as the average length of a solar day in the year 1900.
A solar day is the time interval between successive appearances of the Sun at its highest point each day.
So that would be 1 / 86,400 of a day!
In 1967, we were able to take advantage of new technology in the atomic clock.
A clock that uses the frequency of the light emitted from the cesium-133 atom.
The second is now defined as 9,192,631,700 times the period of oscillation of radiation from the cesium atom.

16. Dimensional Analysis
The is a term given to the process for converting units from system to system, or even within the same system.
You goal is to use conversion factors to cancel out the units you no longer want, and create the units for your new measurement.
Some conversion factors are:
1 in = 2.54 cm
1 kg = 2.2 lbs
1 km = 0.62 mi
1 oC = 9/5(oF) + 32

17. Prefixes Prefix Symbol Number pico- p .000000000001 nano- n .000000001
micro- μ
milli- m
.001
centi- c
.01
deci- d .1
kilo- k
1000
mega- M
1,000,000
giga- G
1,000,000,000

18. Converting Units Time to try a couple of conversions.
Convert 7.35 in to cm
First write down your given information
7.35 in X
2.54 cm
1 in
Then multiply by conversion factor.
Notice the unit we want to go away is put on the bottom so it divides out!
18.669 cm
Now multiply/divide the numbers as shown.
18.7 cm
Label with the units that are left over.
Don’t forget significant figures!

19. Another Example
Try one that is a little tougher and involves multiple steps.
Convert 75 mph to m/s.
75 mph x
1 km x
1000 m x
1 h x
1 min =
0.62 mi
1 km
60 min
60 s
34 m/s

20. Interesting Facts Measurement Value One light-year 1 x 1025 m
Mean distance from Earth to Moon
4 x 108 m
Mean radius of Earth
6 x 106 m
Size of cells of most living organisms
1 x 10-5 m
Diameter of a proton
1 x m
Average age of a college student
6 x 108 s
Time between normal heartbeats
8 x 10-1 s
Duration of a nuclear collision
1 x s

21. Building Blocks of Matter
We all know that matter is made of many small particles called atoms.
We also know that atoms are made of even smaller particles called protons, neutrons, and electrons.
But what are protons, neutrons, and electrons made of?

22. Quarks
Quarks are particles that make up the more commonly known particles called protons, neutrons, and electrons.
There are six particles that are defined as quarks.
They are named as follows: Up
Down
Strange
Charmed
Bottom
Top
The up, charmed, and top quarks have a charge +2/3 that of a proton.
So a proton consists of two up quarks and one down quark.
The down, strange, and down quarks have a charge of –1/3 that of a proton.
A neutron consists of two down quarks and one up quark.

23. Coordinate Systems
We are able to model position and distance by using a coordinate system to graph our model.
There are two types of systems
Cartesian coordinate
X-Y Axis
Plane polar

24. Plane Polar
A plane polar system only needs an origin and a line of reference.
The coordinates for any point refer to the distance from the origin and the angle of rotation from the line of reference.
A counter-clockwise rotation gives a positive angle of rotation.
A clockwise rotation gives a negative angle of rotation.
The coordinates are labeled…
(r , θ) where r is the distance from the origin and θ is the angle of rotation.

25. Converting Between Systems
Knowing the polar coordinates, we can convert using one simple transformation
(r , θ)  (r cos θ , r sin θ)  (x , y)
Knowing the Cartesian coordinates, the transformation is a little more complicated
(x , y)  (√x2+y2 , tan-1 y/x)  (r , θ)