Physics Laws & Theorems
Basic

Hooke's Law

The restoring force of a spring is proportional to its extension.

Formula

F=kxF = -kx

Variables

kSpring constant
xDisplacement

Example

A spring with k = 100 N/m stretched 0.2 m pulls back with 20 N.

Did You Know?

Hooke's law holds only up to the elastic limit; stretch a spring too far and it never returns.