Car weight. 1.5t moves at a constant speed of 27km / h. The coefficient of resistance to movement is 0.02

Car weight. 1.5t moves at a constant speed of 27km / h. The coefficient of resistance to movement is 0.02 what power is developed by the car’s engine.

m = 1.5 t = 1500 kg.

V = 27 km / h = 7.5 m / s.

g = 10 m / s2.

μ = 0.1.

N -?

Power N is called a scalar physical quantity, which shows the speed of performing mechanical work: N = A / t.

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

Since the car was moving uniformly, then its movement S is expressed by the formula: S = V * t.

Since the car moves uniformly, its traction force Ft is used to overcome the friction force Ftr: Ft = Ftr.

Ftr = μ * m * g.

Fт = μ * m * g.

A = μ * m * g * V * t.

N = μ * m * g * V * t / t = μ * m * g * V.

N = 0.1 * 1500 kg * 10 m / s2 * 7.5 m / s = 11250 W.

Answer: the power of the car engine is N = 11250 W.