# Two bodies fall from a height of 20 m. Without initial velocity. One of them meets a platform inclined at an angle of 45.

**Two bodies fall from a height of 20 m. Without initial velocity. One of them meets a platform inclined at an angle of 45. The impact point is at a height of 10 m. Is it necessary to determine the fall time of the bodies t1 and t2?**

When the first body hits the platform, the angle of incidence will be equal to the angle of reflection. Immediately after the impact, the body will have only a horizontal velocity component.

The vertical component is v₀ = 0.

It can be assumed that the body fell 2 times from a height of h₁ = 10 m. The total time of the body falling t₁ is equal to twice the time of falling t from a height of h₁ = 10 m.

h₁ = gt² / 2.

2h₁ = gt².

t = root (2h₁ / g);

t = root ((2 * 10 m) / 9.8 m / s²) = 1.42 s;

t₁ = 2t = 2.84 s.

Fall time of the second body:

h₂ = 20 m; t₂ = root (2h₂ / g) = ((2 * 20 m / 9.8 m / s²) = 4.08 s.

Answer: t₁ = 2.84 s, t₂ = 4.08 s.