1. Warm UP: 1. What is the average velocity of a car that moved 60km in 3 hours heading south?
Journal U:

2. Learning Target
I can explain how to find the acceleration of an object.
Today:
Recap Quiz
Acceleration Notes/Video
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3. S and V Quiz Distance b.Time c. Speed d. Velocity
1. Noni walks 4 m/s south. Which of the following best describes Noni’s travel?
Distance
b.Time
c. Speed
d. Velocity
2. Instantaneous speed is measured
At a particular instance
When it reaches the destination
At the starting point

4. 3.  If a total distance of 750 m is covered in a time interval of 25s, the average speed is ______?
4. Which of the following is a measure of velocity?
20 m/s
20 m
20 s
20 m/s south
5. If Jane walks at 2 m/s for 12 s she would travel a distance of ________meters.
6.  How far would you travel moving at 12 m/s for 3 minutes?

5. 7. ______________ describes how fast something is going, whereas, __________ describes how fast something is going and in a certain direction.
8. _____ is a unit of speed:
Meters
Seconds
Kilograms
meters/second
9. What is the formula for SPEED?
10.Define Force.

6. Speed and Acceleration
Measuring motion

7. Measuring Distance Meter – international unit for measuring distance.
1 mm
= 50 m

8. Calculating Speed S = d/t
Speed (S) = distance traveled (d) / the amount of time it took (t).
S = d/t

9. Units for speed
Depends, but will always be a distance unit / a time unit
Ex. Cars: mi./h
Jets: km/h
Snails: cm/s
Falling objects: m/s

10. Calculating speed S = d/t
If I travel 100 kilometer in one hour then I have a speed of…
100 km/h
If I travel 1 meter in 1 second then I have a speed of….
1 m/s

11. Average speed Speed is usually NOT CONSTANT
Ex. Cars stop and go regularly
Runners go slower uphill than downhill
Average speed = total distance traveled/total time it took.

12. 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 d/total t = 60 km/3 h = 20 km/h

13. Question
I travelled 25 km in 10 minutes. How many meters have I travelled?
A) m
B) m
C) .025 m
D) 2.5 m
25 km * 1000m/km = m

14. Question
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

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

16. Question What is the difference between speed and velocity?
Speed is just distance/time. Velocity includes direction as well.
Speed is just distance/time. Velocity includes direction as well.

17. Acceleration Acceleration = speeding up
Acceleration – the rate at which velocity changes
Can be an:
Increase in speed
Decrease in speed
Change in direction

18. Types of acceleration Increasing speed Decreasing 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. Question
How can a car be accelerating if its speed is a constant 65 km/h?
If it is changing directions it is accelerating

20. Calculating Acceleration
If an object is moving in a straight line
Units of acceleration:
m/s2

21. Calculating Acceleration
0 s
1 s
2 s
3 s
4 s
0 m/s
4 m/s
8 m/s
12 m/s
16 m/s

22. Question
A skydiver accelerates from 20 m/s to 40 m/s in 2 seconds. What is the skydiver’s average acceleration?

23. Graphing Acceleration
Can use 2 kinds of graphs
Speed vs. time
Distance vs. time