Q. An engine develops $10\ kW$ of power. How much time will it take to lift a mass of $200\ kg$ to a height of $40\ m$ ($g = 10\ m/\sec^{2}$)
A) $4\ sec$
B) $5\ sec$
C) $8\ sec$
D) $10\ sec$
Explanation
(c) $P = \frac{mgh}{t} = 10 \times 10^{3} \Rightarrow t = \frac{200 \times 40 \times 10}{10 \times 10^{3}} = 8\ sec$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.