Acceleration Acceleration Acceleration is a change in velocity

Acceleration

Acceleration • Acceleration is a change in velocity – Speed or direction

Centripetal Acceleration • Acceleration can mean a change in direction, not just speed • Centripetal acceleration – Acceleration that occurs in a circular motion

Calculating Acceleration •

Acceleration Practice •

More Practice •

Practice • A driver starts his parked car and within 5 seconds reaches a speed of 60 km/hr. What is his acceleration? • With an average acceleration of 2 m/s 2, how long will it take a cyclist starting from rest to reach 10 m/s? • A car traveling at 7. 0 m/s accelerates at the rate of 2 m/s 2 for 2. 0 s. What is the final velocity of the car?

Practice Problems 1. A driver starts his parked car and within 20 seconds reaches a speed of 40 m/s. What is his acceleration? 2. With an average acceleration of 1. 5 m/s 2, how long will it take a cyclist starting from rest to reach 15 m/s? 3. A car traveling at 10 m/s accelerates at the rate of 2. 2 m/s 2 for 5 s. What is the final velocity of the car?

Graphing Accelerated Motion • The slope on a speed vs. time graph is equal to the acceleration.

Interpreting Motion Graphs B C D A 1. Describe what is happening from points A-D if this is a distance vs. time graph. 2. Describe what is happening from points A-D if this is a velocity vs. time graph.

Velocity and Acceleration Lab Trial Distance (m) Time (s) Avg. speed acceleration (m/s) (m/s 2) 1 2 3 For 3 trials: • Copy and complete the above chart • Graph distance vs. time • All three on the same graph • Graph velocity vs. time • All three on the same graph

Multi-step Problems • A giraffe runs 35 meters in 5 seconds. Then, he comes to a stop in 15 seconds. Calculate his acceleration. • A toy car placed at the top of a 6. 0 m ramp is released and rolls down the ramp. The car takes 12. 0 seconds to roll down the ramp. What is the final velocity of the car? What is the acceleration of the car?