Q. If a long spring is stretched by $0.02\ m$, its potential energy is $U$. If the spring is stretched by $0.1\ m$, then its potential energy will be
A) $\frac{U}{5}$
B) $U$
C) $5\ U$
D) $25\ U$
Explanation
(d) $U \propto x^{2} \Rightarrow \frac{U_{2}}{U_{1}} = \left( \frac{x_{2}}{x_{1}} \right)^{2} = \left( \frac{0.1}{0.02} \right)^{2} = 25\ \therefore U_{2} = 25\ U$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.