A load was dropped from a helicopter at an altitude of 300 m after what time will

A load was dropped from a helicopter at an altitude of 300 m after what time will the load reach the ground if the helicopter rises at a speed of 5 m / s?

Given: h (height) = 300 m; Vv (vertical lifting speed) = 5 m / s; g (acceleration due to gravity) ≈ 10 m / s2.

To determine the time of the drop of the load, we apply the formula: h = V0 * t + a * t ^ 2/2 = -Vw * t + g * t ^ 2/2.

300 = -5 * t + 10 * t ^ 2/2.

5t ^ 2 – 5t – 300 = 0 | : five

t ^ 2 – t – 60 = 0 | : five

Discriminant: D = b ^ 2 – 4ac = 12 – 4 * 1 * (-60) = 241.

Fall time (roots of the equation): t1 = (-b + √D) / 2a = (1 + √241) / 2 = 8.262 s (correct).

t2 = (-b – √D) / 2a = (1 – √241) / 2 = -7.262 s (wrong).