Q. A spring with spring constant $k$ when stretched through $1\ cm$, the potential energy is $U$. If it is stretched by $4\ cm$. The potential energy will be
A) $4U$
B) $8U$
C) $16U$
D) $2U$
Explanation
(c) Potential energy $U = \frac{1}{2}kx^{2}$
$\therefore U \propto x^{2}$ [If $k =$ constant]
If elongation made 4 times then potential energy will become 16 times
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.