Changing Velocity
Constant velocity vs. Changing velocity Velocity is either constant or changing. To be constant, the magnitude and the direction can not change.
Constant velocity vs. Changing velocity We have a changing velocity if ANY of the following change Magnitude of the velocity Direction of the velocity
Try It! If Kareem Cheese drives his car at 120 km/h north and then turns around to go 120 km/h south, does he have a constant velocity? Are his speeds on his north bound and south bound trip the same?
Acceleration Any time we change speed or direction, we have a change in velocity. The measurement of this change in velocity is called acceleration. Is acceleration a scalar or vector quantity?
TRY IT! Hal Apenyo races his car from a stand still to 50m/s. He does this in 4.20 seconds. What is his acceleration? m/s/s
Try it! How long will it take Pete Abred to get his car from a stand still to 75 m/s if his acceleration is 20m/s/s? 3.75 seconds
Acceleration in Action! Watch the video and think about when and why there are changes in motion, velocity, and acceleration. Bugatti Veyron vs Typhoon Jet Bugatti Veyron vs Typhoon Jet