Determine the speed of a body thrown at a speed of 15 m / s. From a height of 10m. Air resistance is neglected.

Data: V1 (throw speed) = 15 m / s; h1 (height at which the body was located) = 10 m; h2 (height at the moment of falling) = 0 m; air resistance is not taken into account, the fall is considered vertical.

Constants: g = 9.81 m / s2 ≈ 10 m / s2.

According to the law of conservation of energy:

Ek1 + En1 = Ek2 + En2.

0.5 * m * V12 + m * g * h1 = 0.5 * m * V2 ^ 2 + m * g * h2.

0.5 * V12 + g * h1 = 0.5 * V2 ^ 2.

V2 ^ 2 = 2 * (0.5 * V12 + g * h1) = V1 ^ 2 + 2 * g * h1.

V2 = √ (V1 ^ 2 + 2 * g * h1) = √ (152 + 2 * 10 * 10) = √425 = 20.61 m / s.