Question

2057 Q.No. 9 a A typical car weighs about 1200 N. If the

coefficient of rolling friction is ur = 0.015. What horizontal
force is needed to make the car move with constant speed of
72 km/h on a level road? Also calculate the power developed
by the engine to maintain this speed.
Ans. 18 N, 360 W

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Answer 1

18N & 360W

Step-by-step explanation:

Here,

Velocity of car (v) = 72 ∗ 1000 / 60∗60 = 20m/s

weight of car = 1200N

We have,

μr = Fs / R

Fs = μr ∗ R = 0.015 ∗ 1200 = 18N

Power developed by the engine = 18 ∗ 20 =360W

Hope this helps!!!