# Title Image Description Video
1 Throw Objects

Motion and the Center of Mass

Screw a light bulb into the center and toss to someone. The light bulb shows the center of mass. Change the center of mass of the disc by exchanging the foam plug for a lead weighted plug. Move the bulb to the new center of mass (off center). Hold the disc near the center of mass to toss. Don't worry about breaking the light bulb.  
2 Ball on a String

Central Forces

A ball tried to a string. Twirl in a vertical direction so students can see the path of the ball.  
3 Pail of Water, Pail of Nails

Central Forces

Swing a pail filled with water in a large vertical circle just fast enough so that the water doesn't spill out.

The pail may also be filled with nails. They can be heard dropping away and hitting the pail at the top of the swing, if swung just right.

Video 1

Video 2