1. Foundations for Physics
Dr. Gluck
Unit 1.1
Laws of Motion, Velocity, Displacement, and Acceleration
PS 3-(9-11)-8a
Text Chapter 1: Describing the Physical Universe

2. Guiding Questions
How is adding displacement different from adding distance?
How is calculating speed different from calculating velocity?
How is determining velocity different than determining speed or acceleration?
How can we determine position, speed, or velocity from a graph?

3. Forces and Motion Describing the Physical Universe
1.1 What is Physics?
1.2 Distance and Time
1.3 Speed

4. Chapter 1.1 Objectives and Vocabulary
natural law
experiment
analysis
mass
system
variable
macroscopic
scientific method
independent variable
dependent variable
hypothesis
controlled variable
experimental variable
model
Explain what makes up the universe.
Describe how the scientific method is used.
Explain the effects of energy on a system.

5. What is Physics?
Finding the simplest and least complicated explanation.
Observe HOW things work.
Form connections between cause and effect.

6. Has the ability to cause change
Everything around us
Universe
Matter
Energy
Has mass and volume
Has the ability to cause change

10. Frame of Reference
System to determine or measure position based on the motion/position of the observer.

12. Natural Laws All events in nature obey natural laws.
Natural laws do not change.
Consistency - reliability of successive results or events
Accuracy - how close is the result to the true value?
Natural laws are based on human experiences.

13. Experimentation - carefully designed simulations that are used to analyze (interpret and understand) natural laws.
Experiments have variables - factors that effect the behavior of the experimental system.
2 types of variables:
Experimental - looked at in the experiment
Independent Variable – controlled by YOU
Dependent Variable – changes based on IV
Control - something to compare the experimental variable to..

14. What are the variables?
Independent variable
Dependent variable

16. System- collection of matter and processes that occur in a certain space and can be studied.

18. Energy is the ability to cause change.
Energy of a System
Energy is the ability to cause change.
Energy can take on many forms.
The forms of energy can change from one to another but the TOTAL amount of energy in a system is CONSTANT.

19. Systems in nature want to be stable. Stability is important.
In nature, stability means LOW ENERGY.
Therefore, in nature, systems tend to go from higher energy levels toward lower energy levels in order to reach stability. This is true in all aspects of science..
HIGH E = UNSTABLE
LOW E = STABLE

20. Car is unstable due to its height.
HIGH POTENTIAL ENERGY
Car is more stable at a lower height
LOW POTENTIAL ENERGY

23. 1A Investigation: Time, Distance, and Speed
Key Question:
How is motion described and measured in Physics?
*Students read text section 1.2
AFTER Investigation 1A

24. 1A Investigation Topics
Learn uses and functions of CPO Timer and photogates.
Set car to travel at constant speed.
Measure time intervals.
Calculate speed from time interval measurements.
Graph position vs. timer for car traveling down track.

25. Chapter 1.2 Objectives and Vocabulary
Express distance measurements in both English and metric units.
Measure time intervals in mixed units.
Distinguish between independent and dependent variables.
Construct graphs.
Convert between different units of time.
distance
length
English system
metric system
time interval
second

26. Can you hit the bull's-eye?
Three targets with three arrows each to shoot.
Both accurate and precise
Precise but not accurate
Neither accurate nor precise
How do they compare?
Can you define accuracy vs. precision?

27. Accuracy Precision Closeness to the true value
Reproducibility of results

28. DISTANCE TIME Our measurements: must be precise (reproducible)
Should be accurate (as close to the true value as possible)
3. must have units to communicate value
In physics, we use two common measurements:
DISTANCE
Amount of space between two points
Measured in units of length
TIME
A particular moment (12:00 pm)
A quantity of time (3 hours)
3. Time Interval – “how much time did it take…?”

30. ANSWER: 13,510 seconds Convert 3:45:10 into seconds.
3 hrs x 3600 sec = 10,800 sec hr
45 min x 60 sec = 2,700 sec
min
= sec

31. Dependent variable
Independent variable

32. 1B Investigation: Systems, Energy and Change
Key Questions:
Why do things change?
Why do things change by only a certain amount?
*Students read text section 1.3
AFTER Investigation 1B

33. 1B Investigation Topics
Measure time intervals.
Calculate speed from time interval measurements.
Identify variables in an experiment.
Identify dependent and independent variables.
Control variables in an experiment.
Compare speeds and energy of car.

34. Chapter 1.3 Objectives and Vocabulary
Define speed.
Express an object's speed using various units.
Calculate speed, distance or time given two of the three quantities.
List the steps for solving physics problems.
speed
constant speed

35. What does this sign tell you??
Your text here
25 miles per hour
25 miles
hour
“per” means “divide”
RATIO

36. Speed (v=d/t)
Distance divided by time.
Is a ratio: a relationship between distance and time
If you follow the speed limit, you will travel 25 miles in 1 hour. d v t