The body is thrown horizontally from a height of 20 m at a speed of 15 m / s. How long does it take for the body

The body is thrown horizontally from a height of 20 m at a speed of 15 m / s. How long does it take for the body to fall to the ground? At what distance from the place of throwing horizontally will the body fall and what will be its speed at the moment of falling?

V0 = 15 m / s.

h = 20 m.

g = 10 m / s2.

t -?

L -?

The motion of a body can be divided into two types: horizontally, it moves uniformly with a velocity V0, vertically, it is uniformly accelerated with an acceleration of gravity g.

The flight range of the body L is expressed by the formula: L = V0 * t, where V0 is the throwing speed, t is the flight time of the body.

Vertically, the body moves uniformly with the acceleration of gravity g, so h = g * t ^ 2/2.

The fall time of the body will be the flight time: t = √ (2 * h / g).

t = √ (2 * 20 m / 10 m / s2) = 2 s.

L = 15 m / s * 2 s = 30 m.

V = √ (V0 ^ 2 + V1 ^ 2).

V1 = g * t.

V1 = 10 m / s2 * 2 s = 20 m / s.

V = √ (15 m / s) ^ 2 + (20 m / s) ^ 2) = 25 m / s.

Answer: t = 2 s, L = 30 m, V = 25 m / s.