The car moves at a speed of 54 km / h while developing a power of 6 kW. determinant of thrust force.

V = 54 km / h = 15 m / s.

N = 6 kW = 6000 W.

Fт -?

The power of a car N is the speed at which it performs mechanical work A: N = A / t, where t is the time it takes to complete the work.

We express mechanical work A by the formula: A = Ft * S, where Ft is the thrust force of the car engine, S is the movement of the car.

With uniform motion, the ratio of the traversed path S to the time of its passage t is called the speed of movement V: V = S / t.

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

Fт = N / V.

Fт = 6000 W / 15 m / s = 400 N.

Answer: when driving, the car engine develops a traction force Ft = 400 N.