1. Chapter 11: Motion
Section 11.3
Acceleration

2. Acceleration The rate at which velocity changes is acceleration.
Acceleration can be described as:
Change in speed
Change in direction
Change in both
Acceleration is a vector.
The SI unit for acceleration is m/s2.
Constant acceleration is a steady change in velocity. (Think of an airplane taking off.)

3. Calculating Acceleration
For objects moving in a straight line acceleration can be found using the following formula:
Acceleration = change in velocity
Total time OR
Acceleration = (vf - vi) t

4. More Calculations
Acceleration can be positive or negative. (Think about speeding up or slowing down.)
Solve:
A car traveling at 10 m/s starts to decelerate steadily. It comes to a complete stop in 20 seconds. What is its acceleration?

5. Graphs of Accelerated Motion
The slope of a speed-time graph is acceleration.
Constant acceleration is shown by a linear graph.
If the slope is positive, the acceleration is positive.
If the slope is negative, the acceleration is negative.