1. Today’s Agenda…9-1 
Bellringer: What is the difference between speed and velocity?
Take up HW
Notes on Acceleration
BrainPop on Acceleration

2. Acceleration
Study Pack #11

3. Today’s Goals… I can describe motion with acceleration.
I can calculate acceleration.

4. REVIEW What is motion? How do we know an object is in motion?
How do we measure motion?
What is the difference between speed and velocity?
How do we find speed?

5. Acceleration
Consider this: a car is stopped at a red light, when the light changes the driver gently steps on the accelerator and the car speeds up or accelerates
In everyday language acceleration means “the process of speeding up”

6. Acceleration Acceleration is the rate at which velocity changes
Remember that velocity is speed and direction
Acceleration is increasing speed, decreasing speed, or changing direction

7. Increasing Speed
Any time the speed of an object increases it experiences acceleration
What are some examples of acceleration?
A car that moves from a stopped position
runners

8. Decreasing Speed Decreasing speed is also acceleration
Called negative acceleration or deceleration
What are some examples of deceleration?
A ball rolling to a stop
A car coming to a red light
An airplane landing

9. Changing Direction
Remember that velocity involves both speed and DIRECTION, so a change in direction is also acceleration
You may think that a car traveling at constant speed does not accelerate, but actually it does because it will change directions!

10. Changing Direction Examples: Race car drivers rounding a turn
Any circular motion
The seats on a Ferris wheel

11. Did you get it?
How is it possible for a car to be accelerating if its speed is steady at 65 mph?

12. Calculating Acceleration
To determine the acceleration, you must calculate the change in velocity during each unit of time
Acceleration = Final Velocity – Initial Velocity divided by time
Initial means beginning, final means ending
What are the units for velocity?
The units are meters per second per second, which is written m/s2 or km/h2

13. Try it!
A car advertisement states that a certain car can accelerate from rest to 90 km/hr in 9 seconds. What is the car’s acceleration?

14. Acceleration
More about acceleration!

15. Today’s Goals… I can describe motion with acceleration.
I can calculate acceleration.