Q. The decrease in the potential energy of a ball of mass $20\ kg$ which falls from a height of $50\ cm$ is
A) $968\ J$
B) $98\ J$
C) $1980\ J$
D) None of these
Explanation
(b) $\mathrm{\Delta}U = mgh = 20 \times 9.8 \times 0.5 = 98\ J$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.