Acceleration Mr. Monroe October 30, 2007
Acceleration ~ is the change in rate of volocity.
change in velocity Acceleration = time taken to change
Acceleration ~ is the change in rate of volocity. change in velocity Acceleration = time taken to change (V f - V i ) Acceleration = t
Example with POSITIVE acceleration Positive acceleration Initial velocity = 0 km/hr Final velocity = 80 km/hr Time = 15 seconds
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 = seconds
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 = seconds Acceleration = 5.33 km/hr/sec
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 = seconds Acceleration = km/hr/sec
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?
Vf = 0 m/s Vi = 400 m/s T = 3 s (0 m/s) – (400 m/s) = m/s/s (Note that this is negative, hence the sign) 3 s
A car hits a tree going 60 miles per hour. It takes the occupant.1 seconds to stop. What is her acceleration?
Vf = 0 miles/hour Vi = 60 miles/hour T =.1 s (0 miles/hour) – (60 miles/hour) = miles/hour/second (Note that this is negative).1 s This is probably not a survivable accident.
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?
Vf = 0 miles/hour Vi = 60 miles/hour T =.5 s (0 miles/hour) – (60 miles/hour) = miles/hour/second.5 s This is a very survivable accident.
End of first part of presentation.
A cross-country runner accelerates at a rate of 1 meter per second, per second. How fast will he be running in 5 minutes?
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
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?
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.