Resonata is an educational online physics toy. The interactive Java applet generates geometric animations representing a spring system, designed to demonstrate many of the universal features of waves.
A series of weights are linked together, so that each is pulled towards its nearest neighbours. This allows waves of motion to travel along the chain. A driving force is applied to one weight, which produces such a wave. Clicking in the display area pulls the nearest weight towards the cursor. When you release the cursor, it twangs back.
Resonata is designed by Fergus Ray Murray who has many more animations and interactive toys available at his website.
Via J-Walk Blog
Here’s my growing list of Interactive Sound Sites which are both fun and educational to play with.