The body moves according to the law S = 14t + t2 under the action of a constant

The body moves according to the law S = 14t + t2 under the action of a constant force of 10 N. Determine the power developed by a moving body 3 s after the start of movement.

P = F * V

This equation has the form S = V0 * t + a * t ^ 2/2. From this we see that V0 = 14 m / s, and the acceleration A = 0.5 m / s ^ 2

V = V0 + A * t = 14 + 0.5 * 3 = 15.5 m / s

And we get P = 10 * 15.5 = 155 W