This classic demonstration consists of a large bowl filled with dried black beans.

To demonstrate how the density of a material affects it's buoyancy. Also shows how the idea of buoyancy can apply in media other than water.

• Bowl filled with beans
• Steel ball
• Ping-pong ball

1. Bury ping pong ball deep into the beans.
2. Place steel ball on top of the beans.
3. Next, gently shake the bowl. As you do this the ping pong ball will rise to the surface and the steel ball will sink to the bottom. This shows that the density of the beans is somewhere between that of the two balls.