The body freely falls from a height h without initial velocity. In the last second, it travels the distance S = 25 m. Find h.

Data: S (distance traveled in a second before falling) = 25 m.

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

1) Speed 1 second before falling: S = V * t + g * t1 ^ 2/2, whence V = (S – g * t1 ^ 2/2) / t1 = (25 – 10 * 1 ^ 2/2 ) / 1 = 20 m / s.

2) The duration of the fall: t = tн + t1 = V / g + t1 = 20/10 + 1 = 3 s.

3) Initial height: h = g * t ^ 2/2 = 10 * 3 ^ 2/2 = 45 m.

Answer: The fall of a given body should have started at a height of 45 m.