A stone weighing 400 g is thrown horizontally from a tower 20 m high at a speed of v0 = 10 m / s.

A stone weighing 400 g is thrown horizontally from a tower 20 m high at a speed of v0 = 10 m / s. Neglecting the air resistance, determine the potential energy after 1 s of flight.

From the ZSE we get: m * V0 ^ 2/2 + m * g * h = m * V ^ 2/2 + Ep, Ep = m * (V0 ^ 2 – V ^ 2) / 2 + m * g * h

Vy = V0 + g * t = 10 + 10 = 20 m / s, Vx = V0, since the movement along the x axis is uniform. Using the projections of the velocities, we find V = (Vy ^ 2 + Vx ^ 2) ^ 1/2 = 500 ^ 1/2

Ep = 0.4 * (100 – 500) / 2 + 0.4 * 10 * 20 = 0