Perfect Elastic Physics
Press space to toggle showing the nodes.
Press the ► button to play the simulation:
>Click on nodes to "freeze" them, click and drag to move them.
>Click and drag on the stage to move the nodes.
Press the + button to pause the simulation and add/connect nodes.
>To add a node, click on the stage.
>To connect a node, click on the first (should turn dark), then click on the second, and the two should be linked. You can cancel this by re-clicking the first node after it has turned dark.
Press the -- button to begin deleting nodes.
>To delete a node, click on it. Any links to the node will be erased as well.
Probably one of the smoothest elastic physics simulations in Scratch. It is called perfect not because the physics are exact but because they are ideal. You can make transverse waves, longitudinal waves, and standing waves. :)