# Under the action of a force of 2 kN, a body with a mass of 500 g moves with acceleration.

**Under the action of a force of 2 kN, a body with a mass of 500 g moves with acceleration. Determine the speed of body movement if the body action time is 0.04 s.**

F = 2kN = 2000 N.

m = 500 g = 0.5 kg.

t = 0.04 s.

V0 = 0 m / s.

V -?

Since the body is acted upon by a force F constant in value and direction, it will move uniformly with acceleration a. The speed of the body V at uniformly accelerated motion is expressed by the formula: V = V0 + a * t, where V0 is the initial speed of motion, t is the time of motion.

We express the acceleration a according to Newton’s 2 law: a = F / m.

V = V0 + F * t / m.

We assume that the body began its motion from a state of rest V0 = 0 m / s, then the formula will take the form: V = F * t / m.

V = 2000 N * 0.04 s / 0.5 kg = 160 m / s.

Answer: the body will have a speed of V = 160 m / s.