Under the action of a force of 0.4 kN, the body was transferred in 20 s to a distance of 40 m. What is the power of this body?

F = 0.4 kN = 400 N.

t = 20 s.

S = 40 m.

∠α = 0 °.

N -?

Power N is called the speed of performing mechanical work A. Power N is determined by the formula: N = A / t, where A is mechanical work, t is the time of performing mechanical work.

The work of force A is determined by the formula: A = F * S * cosα, where F is the force that acts on the body, S is the movement of the body, ∠α is the angle between the direction of action of the force F and the movement of the body S.

Since the body moves in the direction of the action of the force F, then ∠α = 0 °, cos0 ° = 1.

N = F * S / t.

N = 400 N * 40 m / 20 s = 800 W.

Answer: the power when driving is N = 800 W.