1. Chapter 4
Linear Motion

2. Position, Distance, and Displacement
being able to describe an object’s location is important when things start to move
object’s can have positive or negative positions

3. Position, Distance, and Displacement
an object has a __________ position if it is to the right of or above the origin (zero point)
an object has a ____________ position if it is to the left of or below the origin (zero point)
if an object’s position is changing, the object is in motion

4. Position, Distance, and Displacement
Distance & Displacement
Definitions:
_______________: measurement of the actual path traveled
_________________: the straight-line distance between 2 points with direction

5. Position, Distance, and Displacement
A mouse ran in a curved path from his mouse hole to the cheese.
Which path shows the mouse’s displacement? ___________ B
Which path shows the distance the mouse traveled? ________ A
What is the mouse’s displacement? ____________
2 meters
What distance does the mouse travel? ____________
After running 4 meters from his hole to the cheese, the mouse returned to his hole (using the same path).
4 meters
What total distance did the mouse run? ____________
What is the mouse’s total displacement? ____________
4+4= 8 meters
2-2 = 0 meters

6. Notes: Vectors and Scalar
Vectors and Scalars:
You may have noticed that direction sometimes matters.
What are two quantities we have learned about so far where direction matters?
_________________
__________________
If direction matters, we say that the quantity is a _____________.
If direction doesn’t matter, we say that the quantity is a _______________.

7. 4.1 Motion is Relative
Motion describes how fast something is going compared to something else.
The cars move relative to the track

8. Motion is Relative cont’
The earth is moving but relative to the earth we are not moving.
In a vehicle you are at rest because relative to the vehicle you are not moving

9. Speed: _________ traveled per unit of _________
If you change positions, it takes time to get to your new position
If you care about both the distance traveled and the time it takes, you are concerned with speed.
Speed: _________ traveled per unit of _________

10. 4.2 Speed Speed tells us how __________ an object is moving
The units of speed are ______________
The unit is often written with symbols instead: __________
The definition equation for speed is:

11. Example If a cheetah is traveling 80 miles per hour
That means it travels 80 miles in one hour
Speed = 80 miles/1hour

12. Instantaneous speed This is the _____________________.
Your car speedometer measures _______________.

13. Average speed The definition equation for speed is:
__________________: total distance traveled divided by the time it takes to travel that distance
The definition equation for speed is:
If you go on a trip and you estimate how long it will take you may use average speed.

14. Average speed s = ? d = t = The average speed is _________
Sample Problem:
If you traveled 100 m in 50 seconds, what was your average speed?
s = ?
d =
t =
The average speed is _________

15. Units Remember your units do not disappear
If you divide miles by hours you get miles/hours for units

16. 4.3 Velocity Velocity is a _________ with ___________
An example of velocity would be 25 m/s West
the speed is 25 m/s
the direction is West
both of these are needed to describe velocity

17. Constant Velocity This is a ___________ in a ______________
Constant velocity cannot turn!

18. 4.4 Acceleration Your Objective:
You will be able to compare and contrast Acceleration, Speed and Velocity.
You will know the formulas and be able to solve for Acceleration, Speed and Velocity

19. 4.4 Acceleration
Acceleration is the rate at which the velocity is changing.
Acceleration= change of velocity/time

20. Changing motion
When ever you change your state of motion you are accelerating.

21. Deceleration
This is slowing down.
The opposite of acceleration.

22. Change in Direction
When you go around a curve you are always accelerating.

23. Change in Speed
Acceleration can also be the change of speed divided by time.
Providing the motion is in a straight line.

24. 4.5 Free Fall Your Objective:
You will be able to calculate the speed and distance of an object in free fall.

25. 4.5 Free Fall
When something drops straight down it____________________.

26. Falling Objects
To accelerate under the force of gravity is to _________________.
Acceleration of gravity is about ___________

27. Falling Objects
The math for the instantaneous speed of falling objects is v = g x t

28. Rising objects If you throw something straight up two things happen:
On the way up it __________________
On the way down it ________________

29. Rising objects cont
At each distance going up and down the speed of the object is proportional.

30. 4.6 Free Fall how far Your Objective:
You will be able to calculate the vertical distance an object cover in a given amount of time when in free fall

31. 4.6 Free Fall how far
To find the distance of a falling object you need to use the following equation
This takes in account the acceleration of gravity.

32. 4.6 Free Fall how far

33. 4.7 Graphs and Motion Your objective:
To determine an objects motion by Analysis of speed vs. time and distance vs. time graphs.

34. 4.7 Graphs and Motion Speed vs. Time graphs v is on the y axis
t is on the x axis
The ____________ of the line will be the ____________________.

35. Graphs cont. Distances vs. time d is on the y axis t is one the x axis
Free fall will make a curved line This is because t is squared (d=1/2g*t2)

36. 4.7 Graphs and Motion

37. 4.8 Air Resistance Air resistance slows down how fast an object falls.
The air is pushing slightly up causing the object to slow.