The initially resting body of mass m = 2 kg is acted upon by a force F = 10 N for t = 10 s.

The initially resting body of mass m = 2 kg is acted upon by a force F = 10 N for t = 10 s. Determine E-kinetic energy of the body at the end of the tenth second.

m = 2 kg.

F = 10 N.

t = 10 s.

V0 = 0 m / s.

Ek -?

The kinetic energy of the body Ek is determined by the formula: Ek = m * V ^ 2/2, where m is the mass of the body, V is the speed of movement of the body.

According to Newton’s 2 law: m * a = F, where m is the mass of the body, a is the acceleration of the body’s motion, F is the force.

According to the definition, the acceleration of the body a is determined by the formula: a = (V – V0) / t.

Since V0 = 0 m / s, then a = V / t.

m * V / t = F.

V = F * t / m.

Ek = m * (F * t) ^ 2/2 * m ^ 2 = (F * t) ^ 2/2 * m.

Ek = (10 N * 10 s) ^ 2/2 * 2 kg = 2500 J.

Answer: the kinetic energy of the body is Ek = 2500 J.