Q. An engine of power 7500 W makes a train move on a horizontal surface with constant velocity of $20\ ms^{- 1}$. The force involved in the problem is
A) 375 N
B) 400 N
C) 500 N
D) 600 N
Explanation
(a) Power = 7500, W = 7500 $Js^{- 1}$, velocity $v = 20\ ms^{- 1}$
$P = Fv$ or $F = \frac{P}{v} = \frac{7500\ Js^{- 1}}{20\ ms^{- 1}} = 375\ N$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.