# Getting work out of kinetic energy

by cdot
Tags: energy, kinetic, work
 PF Gold P: 936 Getting work out of kinetic energy Hook a (weakish) spring on to the car as it's moving. Observe the maximum extension, x, (preferably by taking a rapid succession of pictures). Hope to find that $$\frac{1}{2}mv^2 = \frac{1}{2}kx^2.$$ Negligible energy dissipated in collision.