1. Acceleration Mr. Monroe October 30, 2007

2. Acceleration ~ is the change in rate of volocity.

3. change in velocity Acceleration = ---------------------------------------- time taken to change

4. Acceleration ~ is the change in rate of volocity. change in velocity Acceleration = ---------------------------------------- time taken to change (V f - V i ) Acceleration = ---------------------------------------- t

5. Example with POSITIVE acceleration Positive acceleration Initial velocity = 0 km/hr Final velocity = 80 km/hr Time = 15 seconds

6. Example with POSITIVE acceleration Positive acceleration Initial velocity = 0 km/hr Final velocity = 80 km/hr Time = 15 seconds (80 km/hr - 0 km/hr) Acceleration = ---------------------------- 15 seconds

7. Example with POSITIVE acceleration Positive acceleration Initial velocity = 0 km/hr Final velocity = 80 km/hr Time = 15 seconds (80 km/hr - 0 km/hr) Acceleration = ---------------------------- 15 seconds Acceleration = 5.33 km/hr/sec

8. Example with NEGATIVE acceleration Negative acceleration Initial velocity = 80 km/hr Final velocity = 0 km/hr Time = 15 seconds (0 km/hr - 80 km/hr) Acceleration = ---------------------------- 15 seconds Acceleration = -5.33 km/hr/sec

9. A plane hits a mountain at a speed of 400 meters per second, and it takes the plane 3 seconds to stop. What is the acceleration of the plane?

10. Vf = 0 m/s Vi = 400 m/s T = 3 s (0 m/s) – (400 m/s) ------------------------ = - 133 m/s/s (Note that this is negative, hence the sign) 3 s

11. A car hits a tree going 60 miles per hour. It takes the occupant.1 seconds to stop. What is her acceleration?

12. Vf = 0 miles/hour Vi = 60 miles/hour T =.1 s (0 miles/hour) – (60 miles/hour) ----------------------------------------- = - 600 miles/hour/second (Note that this is negative).1 s This is probably not a survivable accident.

13. A car hits a tree going 60 miles per hour. It takes the occupant.5 seconds to stop, because she was wearing a seat belt. What is her acceleration?

14. Vf = 0 miles/hour Vi = 60 miles/hour T =.5 s (0 miles/hour) – (60 miles/hour) ---------------------------------------- = - 120 miles/hour/second.5 s This is a very survivable accident.

15. End of first part of presentation.

16. A cross-country runner accelerates at a rate of 1 meter per second, per second. How fast will he be running in 5 minutes?

17. A cross-country runner accelerates at a rate of 1 meter per second, per second. How fast will he be running in 5 minutes? The cross-country runner must be Chuck Norris 1 m /s 5 minutes 60 seconds ------- x -------------- x ------------------ = 300 m/s s 1 1 minute Most airplanes could not go this fast

18. Brett’s car accelerates from 0 meters per second, to 5 meters per second in 2.3 seconds. What is its rate of acceleration? At that rate of acceleration, how fast will it be going in 6 hours?

19. Brett’s car accelerates from 0 meters per second, to 5 meters per second in 2.3 seconds. What is its rate of acceleration?At that rate, how fast will it be going in 6 hours? Vf = 5 m/s Vi = 0 m/s T = 2.3 s (5 m/s) – (0 m/s) ------------------------ = 2.2 m/s/s is the rate of acceleration 2.3 s At that rate, how fast will it be going in 6 hours? 2.2 m/s 6 hours 60 min 60 seconds ------------ x--------------- x -------------- x -------------- = 47,520 meters per second s 1 1 hour1 min At that speed, you would be getting around the world, at the equator, in about 14 minutes.