Q. An electric motor creates a tension of 9000 N in a hoisting cable and reels it in at the rate of $2\ ms^{- 1}$. The power of the electric motor is
A) 18 kW
B) 15 kW
C) 81 W
D) 225 W
Explanation
(a) $P = Fv$
$= 9000N\ \times 2\ ms^{- 1} = 18000Js^{- 1}$
$= 18000\ W = 18\ kW$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.