The equation of motion of the body has the form x = -5 + 2t + 0.5t, determine the kinetic energy of the body

The equation of motion of the body has the form x = -5 + 2t + 0.5t, determine the kinetic energy of the body in t = 2s after the start of motion. Body weight m = 0.6 kg

Initial data: the equation of body motion x = -5 + 2t + 0.5t ^ 2; t (time after the beginning of body movement) = 2 s; m (body weight) = 0.6 kg.

1) Let us define the equation by which the speed of the body changes: V = x ‘= (-5 + 2t + 0.5t ^ 2)’ = 0 + 2 * 1 + 0.5 * 2 * t = 2 + t.

2) Let’s calculate the speed of the body 2 s after the start of movement: V (2) = 2 + 2 = 4 m / s.

3) We calculate the kinetic energy that the body will acquire: Ek = m * V ^ 2/2 = 0.6 * 4 ^ 2/2 = 4.8 J.

Answer: The kinetic energy of the body in 2 s will be 4.8 J.