A spring when extended by x potential energy stored is U. When extended by 2 x , potential energy st

Question

A spring when extended by x potential energy stored is U. When extended by 2 x , potential energy stored is

Professor PC Thomas Classes · Answer

Potential energy of a spring is $U = \frac{1}{2} k x^2$. If extension is $2x$, new energy $U' = \frac{1}{2} k (2x)^2 = 4 \left(\frac{1}{2} k x^2\right) = 4U$.