2 seconds after the throw, the kinetic energy of a body weighing 0.2 kilograms

2 seconds after the throw, the kinetic energy of a body weighing 0.2 kilograms is thrown vertically upward at a speed of 30 meters. A second is equal to.

Data: t (elapsed time after throw) = 2 s; m (the mass of the thrown body) = 0.2 kg; V (the speed with which the body was thrown) = 30 m / s; the body was thrown vertically upward (body movement is slow).

Reference values: g (acceleration due to gravity) = 10 m / s2 = a.

1) The speed of the body after 2 s: V = V0 – a * t = V0 – g * t = 30 – 10 * 2 = 10 m / s.

2) The kinetic energy that the body will possess: Ek = 0.5 * m * V2 = 0.5 * 0.2 * 102 = 10 J.

Answer: The kinetic energy will be equal to 10 J.