The body falls from a certain height H to the ground in t = 10 s. Determine the speed of the body at half height.

Task data: t (total duration of the fall) = 10 s.

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

1) Some height: h = g * t ^ 2/2 = 10 * 10 ^ 2/2 = 1000/2 = 500 m.

2) Half height: h1 = h / 2 = 500/2 = 250 m.

3) Speed at half height: h1 = V ^ 2 / 2g, whence V = √ (2g * h1) = √ (2 * 10 * 250) = 70.71 m / s.

Answer: At half the height, the speed of the falling body will be equal to 70.71 m / s.