Question

A 5kg weight whose motion is constrained by vertically guides is dropped from rest 0.5m onto vertically aligned spring whose stiffness is 10kNm-¹. how fast is the weight travelling when the spring has been compressed by 50mm?

Answer 1

$mgh=\frac{kx^2}2+\frac{mv^2}2,$

$v=\sqrt{2gh-\frac{kx^2}m}=2.2~\frac ms.$