Q. A $50\ kg$ man with $20\ kg$ load on his head climbs up 20 steps of $0.25m$ height each. The work done in climbing is
A) $5\ J$
B) $350\ J$
C) $100\ J$
D) $3430\ J$
Explanation
(d) Total mass $= (50 + 20) = 70\ kg$
Total height $= 20 \times 0.25 = 5m$
$\therefore$ Work done $= mgh = 70 \times 9.8 \times 5 = 3430\ J$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.