Determine the free fall time of a body from a height of 500 m and its speed at the moment it reaches the earth’s surface.

Initial data: h (height from which the body began to free fall) = 500 m; V0 (initial speed) = 0 m / s.

Reference values: g (acceleration due to gravity) ≈ 10 m / s2.

1) Free fall time of a body: h = S = g * t ^ 2/2, whence t = √ (2 * h / g) = √ (2 * 500/10) = 10 s.

2) The speed of the body at the moment of reaching the surface of the earth: Ek = m * V ^ 2/2 = m * g * h = En, whence V = √ (2 * g * h) = √ (2 * 10 * 500) = 100 m / s or V = a * t = g * t = 10 * 10 = 100 m / s.