1. Acceleration

2. Review Speed – how quickly something moves
Velocity – how quickly something moves and in what direction.

3. What is Acceleration?
1. Acceleration is the rate of change of velocity with time.
2. This change in velocity can be caused by:
A. Change in speed
B. Change in direction

4. Types of Acceleration 3. There are 3 types of acceleration:
A. Increasing speed – accelerating
B. Decreasing speed – decelerating
Also called negative acceleration
C. Changing direction – turning (can be at constant speed)

5. Zero Acceleration
If acceleration is zero, velocity cannot be changing. So, velocity is constant and in one direction.
Is acceleration zero here?

6. The Math
4. acceleration equals the change in velocity divided by the change in time.
The formula: a = Vf-Vi t
5. The units: m/s2

7. Example
You are driving from home to school and your velocity goes from 10m/s to 40m/s in sec. What is your acceleration?

8. Example
A roller coaster car rapidly picks up speed as it rolls down a slope. As it starts down the slope, its speed is 4 m/s. But 3 seconds later, at the bottom of the slope, its speed is 22 m/s. What is its average acceleration?

9. Example
If a Ferrari, with an initial velocity of 10 m/s, accelerates at a rate of 50 m/s/s for 3 seconds, what will its final velocity be?

10. Example
A lizard accelerates at 4 m/s2 from 2 m/s to 10 m/s to escape a bird overhead. How long did this take?