Find the time of fall and the final speed of a body freely falling from a height of 45 m?

Initial data: h (height from which the body freely fell) = 45 m; V0 (initial velocity of the body) = 0 m / s.

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

1) The final speed of the body (the law of conservation of energy): Ek = Ep = 0.5 * m * V2 = m * g * h and V = √ (2g * h) = √ (2 * 10 * 45) = √900 = 30 m / s.

2) The duration of the fall of the body: V = g * t and t = V / g = 30/10 = 3 s.

Answer: The time for the body to fall is 3 s; the final speed of the body is 30 m / s.