Question

A 150 kg car engine develops 500 W for each kg. What force does it exert in moving the car at a speed of 20m/s?​

Answer 1

Weight of Car=150 kg
Power=500 W for Each kg

Power is Rate of doing a Work .And Its Denoted in Watt(W).
Here in 1 kg weight Rate of Doing work=500 W

Total Power=Weight×Power of each
=150×500
=75000 W

Speed=20 m/s

Power=Force×Speed
75000=Force×20
Force=75000/20
Force=3750 N

N(Newton) is SI unit of Force

$\boxed{\textsf{Force=3750 N}}$

Answer 2

Solution:

Given:
Weight = 150 kg
Power = 500 W for Each kg
Speed = 20m/s

Now,
Power = Weight × Each power
⇒ 150 × 500
⇒ 75000 Watt

Again,
Power = Force × Speed
⇒ 75000 = Force×20
⇒ Force = 75000/20
⇒ Force = 3750 N

Hence, The Required Force is 3750 N.