You can also click on the picture to download it in .gif format.
You can also click on the picture to download it in .gif format.
Further information on the Theory, Apparatus, and Procedure for this demonstration is available. Bearing track and cars are available in Rockefeller 302. Other carts maybe available in Rockefeller 402 or 403.
The purpose is to show that the center of mass of a stationary system remains constant even when the particles of the system are not stationary.
The objects in question will fly apart when their internal interactions dictate. According to Newton's laws of motion, these pieces of the system will preserve the overall momentum of the system when they come apart. Their velocities will therefore be inversely proportional to their masses (for a two-particle system) and the center of mass will remain at rest.
Equipment needed:
Balance the bearing track on the fulcrum and then place the carts on either side of the fulcrum. Tap the trigger button on one of the bearing carts (you can use one of the masses to do this). The carts will come apart, but the track will remain balanced. This indicates that the center of mass is still over the fulcrum.
Load one of the carts with some extra mass and repeat the experiment. It will be a little more difficult to balance the track this time, and the carts will move with different velocities. As the carts reach the end of the track, be careful to catch them. The lighter cart will reach the end of the track first, displacing the center of mass of the system rather quickly.
To return to the Mechanics Demo Catalogue .
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