The car drives on a straight road at a constant speed of 36 km / h.

The car drives on a straight road at a constant speed of 36 km / h. The drag force of the wheels and the road is 1000 N. Find the engine power of the car in W.

V = 36 km / h = 10 m / s.

Fcopr = 1000 N.

N -?

The power of the car engine N is the ratio of the work performed A to the time of its execution t: N = A / t.

The work A performed by the engine is expressed by the formula: A = Ft * S, where Ft is the engine thrust force, S is the movement of the car.

Since the car moves uniformly in a straight line, the ratio of the distance traveled S to the time it passes t is called the speed: V = S / t.

N = Ft * S / t = Ft * V.

According to 1 Newton’s law, with uniform rectilinear motion, the action of forces on the body is compensated, therefore Fт = Fсopr.

N = Fcopr * V.

N = 1000 N * 10 m / s = 10000 W.

Answer: the car engine has a power of N = 10,000 W.