Q. A spring when stretched by 2 mm its potential energy becomes $4\ J$. If it is stretched by 10 mm, its potential energy is equal to
A) $4\ J$
B) $54\ J$
C) $415\ J$
D) None
Explanation
(d) $U = \frac{1}{2}kx^{2}$ If $x$ becomes 5 times then energy will becomes 25 times $i.e.$ $4 \times 25 = 100\ J$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.