A body weighing 500 g, thrown vertically upward at a speed of 20 m / s, fell back to the ground at a speed

A body weighing 500 g, thrown vertically upward at a speed of 20 m / s, fell back to the ground at a speed of 16 m / s. Determine the work to overcome the air resistance.

Problem data: m (mass of a body thrown vertically upwards) = 500 g (in SI m = 0.5 kg); V1 (body speed after throw) = 20 m / s; V2 (speed at the moment of falling) = 16 m / s.

The work done by this body to overcome air resistance is determined by the formula: A = ΔEk = Ek1 – Ek2 = 0.5 * m * V1 ^ 2 – 0.5 * m * V2 ^ 2 = 0.5 * m * ( V1 ^ 2 – V2 ^ 2).

Let’s perform the calculation: A = 0.5 * 0.5 * (20 ^ 2 – 16 ^ 2) = 36 J.

Answer: The work of this body to overcome air resistance is 36 J.