PURPOSE: To show show that the center of mass is stationary as the pendulum oscillates back and forth.
DESCRIPTION: Two heavy pendulums with total mass equal to the mass of the glider hang from an air track. When the pendula are set into oscillation the center of mass is stationary as the glider and pendula rock to and fro. Note that the above photo shows only the glider and does not show the air track.
EQUIPMENT: Air track, blower, glider with pendula.
SETUP NOTES: The glider is stored in the engineering cabinet. Clean the air track with contact cleaner. Balance the air track in the classroom the day before the demo.
Updated by Jun Qi in 3/1/2000