The body was thrown from a height of 30 m vertically upward at a speed of 10 m / s.

The body was thrown from a height of 30 m vertically upward at a speed of 10 m / s. At what height will the kinetic energy of the body be equal to the potential energy?

h0 = 30 m.

V0 = 10 m / s.

g = 9.8 m / s2.

Ek = En.

h -?

Potential energy is determined by the formula: En = m * g * h.

The kinetic energy of a body is determined by the formula: Ek = m * V ^ 2/2.

At the moment of throwing, the total mechanical energy E is the sum of En and Ek: E = m * g * h0 + m * V0 ^ 2/2.

Since at some height Ek = En, but the total mechanical energy E remains unchanged: E = Ek + En = 2 * En = 2 * m * g * h.

m * g * h0 + m * V0 ^ 2/2 = 2 * m * g * h.

h = h0 / 2 + V0 ^ 2/4 * g.

h = 30 m / 2 + (10 m / s) ^ 2/4 * 9.8 m / s2 = 17.55 m.

Answer: at a height of h = 17.55 m, the kinetic energy will be equal to the potential.