A stone was thrown up from the surface of the earth at a speed of 2 m / s. With what speed will it fall into a pit 10 m deep?

Initial data: V0 (speed with which the stone was thrown) = 2 m / s; h (pit depth) = 10 m.

Constants: g = 10 m / s ^ 2.

1) The height that the stone will reach:

S = (V ^ 2 – V0 ^ 2) / 2a = -V0 ^ 2 / (-2g) = V0 ^ 2 / 2g = 10 ^ 2 / (2 * 10) = 100/20 = 5 m.

2) The height that the stone will pass before falling into the pit: H = S + h = 5 + 10 = 15 m.

3) The speed at which the stone will fall into the pit: H = V ^ 2 / 2g and V = √ (2 * g * H) = √ (2 * 10 * 15) = √300 = 17.32 m / s.

Answer: The stone will fall to the bottom of the pit at a speed of 17.32 m / s.