1. Give yourself a CHECK for each item that is complete.
Give yourself 1/2 for anything started but not finished.
Give yourself an X for anything you did not do.
ADD UP YOUR POINTS and CIRCLE YOUR SCORE.

2. Speed, Velocity, & Acceleration
Measuring Motion
Speed, Velocity, & Acceleration

3. S = d/t Calculating Speed
Speed (S) = distance traveled (d) over a given amount of time (t).
S = d/t

4. S = d/t Calculating speed
If I travel 100 kilometers in two hours then I have a speed of…
50 km/h
If I travel 18 meter in 2 second then I have a speed of….
9 m/s

5. Average speed Speed is usually NOT CONSTANT
Ex. Cars stop and go regularly
Runners go slower uphill than downhill
Average speed = total distance
total time

6. Calculating Average Speed
It took me 1 hour to go 40 km on the highway. Then it took me 2 more hours to go 20 km using the streets.
Total Distance:
40 km + 20 km = 60 km
Total Time:
1 h + 2 h = 3 hr
Ave. Speed:
total distance/total time = 60 km/3 hr = 20 km/hr

7. Question – Discuss with your ELBOW PARTNERS
I ran 1000 m in 3 minutes. Then ran another 1000 m uphill in 7 minutes. What is my average speed?
A) 100 m/min
B) 2000 m/min
C) 10 m/min
D) 200 m/min
E) 20 m/min
Total Dist. = 1000 m m = 2000 m
Total Time = 3 min + 7 min = 10 min
Ave speed = total dist/total time =
2000m/10 min = 200 m/min = D

8. Graphing Speed: Distance vs. Time Graphs
Denver
Phoenix

9. Graphing Speed: Distance vs. Time Graphs
Speed = Slope = Rise/Run
Rise=?
600 km
3 hours
Rise/Run = 600 km/3 hr
= 200 km/hr

10. Question – Discuss with your ELBOW PARTNERS
Below is a distance vs. time graph of runner’s position during a race. What was their AVERAGE speed for the entire race?
Average Speed = Total distance/Total time = 12 km/6 hr
= 2 km/hr
Rise = 12 km
Run = 6 hr

11. Question – Discuss with your ELBOW PARTNER
Below is a distance vs. time graph for 3 runners. Who is the fastest?
Leroy is the fastest. He completed the race in 3 hours (steepest slope)

12. Question – Discuss with your ELBOW PARTNERS
What is the difference between speed and velocity? Give an example of each.
Speed is just distance/time. Velocity includes direction as well.

13. Velocity Velocity – the SPEED and DIRECTION of an object. Example:
Velocity: An airplane moving North at 500 mph
Speed: A missile moving at 200 m/s

14. Combined Velocity
If the relative velocities are in the SAME direction, you ADD them to find the combined velocity.
If the relative velocities are in the OPPOSITE direction, you SUBRTRACT them to find the combined velocity.

15. Question – Discuss with your ELBOW PARTNERS:
You on a moving walkway at the airport. The walkway is moving at m/s north. You are walking at an additional 1.5 m/s in the same direction What is your combined velocity?

16. Acceleration
Acceleration – change in speed over time

17. Question – Discuss with your ELBOW PARTNER
What are the 3 ways that a car can accelerate?

18. Question – Discuss with your ELBOW PARTNER
Increasing speed
Example: Car speeds up at green light
Decreasing speed
Example: Car slows down at stop light
Changing Direction
Example: Car takes turn (can be at constant speed)
screeeeech

19. Calculating Acceleration
Formula for acceleration:
Acceleration = final velocity – initial velocity
time
Units of acceleration:
m/s2

20. Calculating Acceleration - Example
A skydiver goes from 20 m/s to 40 m/s in 2 seconds. What is the skydiver’s acceleration?
a = Vf – Vi = 40m/s – 20m/s = 10m/s/s
t s

21. Question – Discuss with your ELBOW PARTNER:
You’re riding your bike at a speed of 10 m/s when a squirrel darts across the road. You slam on your brakes and come to a stop in 2 seconds. What is your acceleration?

22. Graphing Acceleration: SPEED vs. TIME Graphs
What is happening to speed over time?
What is the acceleration?

23. Graphing Acceleration: SPEED vs. TIME Graphs
Rise = 4 m/s
Run = 2 s
In Speed vs. Time graphs:
Acceleration = Rise/Run
= 4 m/s ÷ 2 s = 2 m/s2

24. Question – Discuss with your ELBOW PARTNER
Run = 3 s
Rise = -6 m/s
How is the speed changing? (speeding up, slowing down, stays the same)
What is this car’s acceleration?
The car is slowing down
Acceleration = rise/run = -6m/s ÷3s = -2 m/s2

25. Graphing Acceleration: DISTANCE vs. TIME Graphs
More distance traveled in each second that passes 
Object is speeding up (positive acceleration)

26. Question – Discuss with your ELBOW PARTNER
Black = positive Red = negative Blue/green = zero
Remember: in distance vs. time graphs:
curved line = accelerating, flat line = constant speed
Which color represents positive acceleration?
Which color represents negative acceleration?
Which color represents zero acceleration?

27. Behavior Expectations for TESTS
Get out your CALCULATOR or come get one to borrow. No phones allowed today.
NO TALKING. If you have a question, ASK ME not your neighbor.
COVER UP YOUR TEST with your whiteboard when possible.
STAY IN YOUR SEAT when finished and slide your test under your whiteboard.
READ QUIETLY until Mrs. Johnson lets you know everyone is finished.
DO YOUR BEST!!! Take your time. You can finish in APP if needed.