Book: # 3

THE PROCEDURE:

The two carts are attached together by the spring.  The spring is compressed and the released.  The carts begin to oscillate about the center of mass.  Weight one cart to twice the weight of the other.  Compress the spring and release it.  The carts again oscillate about the center of mass.

Tie two carts of equal mass together with the rubber band.  Hold the carts at a distance so that the band is tight.  Mark the center point between the two carts.  Release them simultaneously.  The carts will meet at the center point.

Weigh one cart so that it is three times heavier than the other.  Hold the carts apart once more.  Mark a point on the desk that is 1/3 of the distance from the heavier cart.  Release the carts simultaneously.  The carts will meet at the point marked on the desk.