NEB Solutions: Work, Energy and Power

A car of mass 1000 kg moves at a constant speed of [latex]20ms^{-1}[/latex] along a horizontal road where the friction force is 200 N. Calculate the power developed by the engine.

Solution

Given,

Mass of car (m) = 1000 kg

Speed (v) = 20 m/s

Frictional force = 200 N

Power developed by the engine (P) =?

We have, applied force by the engine (F) = frictional force

= 200 N

Now, power [latex](P) = F.v[/latex]

[latex]= 200 \times 20[/latex]

[latex]= 4000\ W.[/latex]