The whale’s power when swimming underwater reaches 4.5 kW at a speed of 10 km / h. Determine the driving force of the whale.

N = 4.5 kW = 4500 W.

V = 10 km / h = 2.8 m / s.

Fd -?

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

We express mechanical work A by the formula: A = Fd * S, where Fd is the driving force of the whale, S is the movement of the whale when it moves.

With uniform rectilinear motion, the body speed V is determined by the formula: V = S / t.

The formula for determining the power of a whale will take the form: N = Fd * S / t = Fd * V.

Fd = N / V.

Fd = 4500 W / 2.8 m / s = 1607 N.

Answer: the driving force of the whale is Fd = 1607 N.