1. Acceleration
Changing Velocity

2. Acceleration
Acceleration - The rate at which velocity changes over time.
An object accelerates if its speed, direction or both changes.

3. What is accelerating?
When an object has an increase in velocity is commonly called positive acceleration.
When an object has a decrease in velocity is commonly called negative acceleration, or deceleration

4. Calculating final velocity  starting velocity average acceleration
=
final velocity  starting velocity
time it takes to change velocity

5. Graphing Acceleration

6. Going in Circles Centripetal Acceleration
An object traveling in a circular motion is always changing its direction. Therefore velocity is constantly changing.

7. Practice Problems
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?
A cyclist accelerates from 0 m/s to 8 m/s in 3 seconds. What is his acceleration ?
A car accelerates from 0 to 30 m/s in 8 seconds, what is it’s acceleration?
A car advertisement states that a certain car can accelerate from rest to 1176m/s in 7 seconds. Find the car’s average acceleration.

8. Answers
6m/s2
2.7m/s2
3.75m/s2
168m/s2

9. Think Pair Share In a pair answer the following questions
Is a fan accelerating?
Can you have constant speed but still be accelerating?
Give an example

10. Critical Thinking
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?
160m/s
Falling objects drop with an average acceleration of 9.8 m/s2. If an object falls from a tall building, how long will it take before it reaches a speed of 49 m/s? 5s