Q. A block of mass $50\ kg$ slides over a horizontal distance of $1m$. If the coefficient of friction between their surface is 0.2, then work done against friction is
A) $98\ J$
B) $72\ J$
C) $56\ J$
D) $34\ J$
Explanation
(a) $W = \mu mgS = 0.2 \times 50 \times 9.8 \times 1 = 98\ J$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.