Physics 2215 Minilab 2: Changing Motion Purpose  Understand how and when objects accelerate.  Understand the nature of acceleration.  Understand the relationship of acceleration, velocity, and position versus time.

Physics 2215 Minilab 2: Changing Motion Acceleration:  Any time the velocity changes, an acceleration occurs.  The direction of acceleration is the same as that of change of velocity. Be careful with this! For example, when a car applies its brakes, the velocity vector and acceleration vectors are in opposite directions.

Physics 2215 Minilab 2: Changing Motion Equipment  Carts with wheels rolling on tracks.  Motion sensors track position, velocity, and acceleration of carts versus time.  4 different track configurations (do one of each)  Single flat track with one motion sensor  Single sloped track (put a wood block under one side of flat track) with one motion sensor.  Double track V-shaped with motion sensors at both ends  Double track, one track flat, the other sloped with motion sensors at both ends  Note for double tracks:  Two groups can work on a double track simultaneously  (analyzing cart motion from the two different sides).  Do not change the slopes of double tracks. Change to the other double track instead.  Motion sensors may need adjustment (see next slide).

Physics 2215 Minilab 2: Changing Motion Adjusting the motion sensor if needed (double track) Make sure that cart can be detected properly by motion detector across the entire length of the track:  Hold cart at “other” (than motion sensor) end of the track.  Open Data Studio activity “Changing Motion.ds”. Click “Start”.  Distance should read approximately 4m for double track for this position.  Gently push cart in direction of motion sensor. Does it track distance smoothly?  If tracking is poor, readjust motion sensor direction (Hint: it tends to track better if motion sensor is tilted slightly “upwards”).