Purpose Understand how and when objects accelerate. Understand the nature of acceleration. Understand the relationship of acceleration, velocity, and position versus time.

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.

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) Flat track Sloped track (put a wood block under one side of flat track) Flat track with pulley and mass Sloped track with pulley and mass Note: You can convert the 4 track configurations on your own.

Tracks with Pulley – Adjusting the string length Cart Table Cart When mass hits floor cart should be about half way on the track Table

Adjusting the motion sensor if needed 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 Capstone activity “Changing Motion.ds”. Click “Record”. Distance should read approximately 2m for this position. If tracking is poor, readjust motion sensor direction (Hint: it tends to track better if motion sensor is tilted slightly “upwards”).