United Scientific Inertia Apparatus

Classic demonstration of an object at rest stays at rest.

• Repeatable results

• Includes two marbles
• Tethered platform for easy recovery and resetting
• Includes activity guide

Inertia is the tendency of an object to either remain in motion or remain at rest, unless acted upon by an outside force. A glass ball is balanced on a platform sitting on a support rod. As a metal arm is pulled back and released, it abruptly pushes the platform out of the way and, given the ball’s inertia, it remains in place. The ball then falls straight down onto the support post which has a small indent to hold the marble.

The platform is connected by a string to a screw on the support rod, so it is easy to recover after being launched. The connecting screw also prevents the metal arm from hitting the ball, so it experiences no outside force. Best if used on a level surface.