Why does the bottom of a slinky not move until the top comes down?

Question

Can someone please explain why the bottom of the slinky doesn’t fall to the floor until the top is finished falling down?

In: 1

Answer 1

So, a Slinky is nothing more than a loose spring with flexible material, like wire or plastic. The spring is strong enough that it tries to hold together, but weak enough that momentum can break that tendency.

So, when you flip over the top of a Slinky, the top part falls to gravity and the rest tries to balance out. But if the top falls underneath the bottom, then evening out those forces means dragging the rest of the toy with it.

The bottom of the spring wants to stay in place, but eventually it gets pulled up and away by the rest.