1. What is acceleration? Section 4-2

2. Changing speed Speeding up and slowing down are changes in speed. To find the change is speed subtract the initial speed from the final speed. Ex. A car goes from 5 m/sec. to 10 m/sec. What is its change in speed.

3. Acceleration A change in speed or direction. When a car speeds up, it is accelerating. When it slows down, it is decelerating. A car turning a corner is accelerating because it is changing direction.

4. Measuring acceleration You must know the change in velocity and the time it takes to change that speed. A = (v f – v i ) / time Suppose a stopped car accelerates to a speed of 150 m/sec and it takes it 10 sec. What is its acceleration? What is its initial speed?

5. H.W. p. 63 check/apply 1-8, skill builder Wkst. 4-2 Enrichment 4-2 Lab challenge 11