A body weighing 0.2 kg is thrown vertically upward at a speed of 30 m / s. find the potential energy of the body in 2s.

The dependence of the body’s speed on time is determined by the formula:

v (t) = vo – at, where v0 is the initial speed, a is the acceleration, t is the time of movement. In this case, a = g is the acceleration of free radiance. Then after 2 s the speed will be:

v (2) = 30 – 2 * 10 = 10 m / s.

By definition, kinetic energy is equal to: E = m * v ^ 2/2, where m is mass, v is velocity:

E = 0.2 * 10 ^ 2/2 = 10 J.

Answer: the sought kinetic energy of the body is 10 J.