PURPOSE: To demonstrate the independence of horizontal and vertical components of motion.

DESCRIPTION: Pulling a release (at center of photograph on right) simultaneously causes the ball on the left side to drop and the ball on the right side to be projected horizontally to the right. They strike the floor at the same time. Click on one of the pictures above for an mpeg video of the action. Listen for the sound of the two falling balls hitting the floor simultaneously.

An exciting new concept, invented by Bill Norwood, is the "square ball" which is used here to prevent the balls from rolling away and becoming lost.

Here is an MPEG video of this demonstration in slow motion

SUGGESTIONS: See Question of the Week #47 for information on using this demonstration to enhance class involvement.

REFERENCES: (PIRA 1D60.20)

EQUIPMENT: Launcher with two square balls.

SETUP TIME: None.