With a vertical lift of a load with a mass of m = 2 kg to a height of H = 4 m, an external vertical force

With a vertical lift of a load with a mass of m = 2 kg to a height of H = 4 m, an external vertical force performed work A = 116 J. How long did the lift last if it was uniformly accelerated without an initial speed?

Given:

m = 2 kilograms – body weight;

h = 4 meters – the height to which the body was lifted;

A = 116 Joules – the work of the external force F, performed to lift the body.

It is required to determine t (second) – the time during which the ascent lasted.

Let’s find the force that acted on the body:

F = A / h = 116/4 = 29 Newtons.

Then this force imparted to the body an acceleration equal to:

a = (F – m * g) / m = (29 – 2 * 10) / 2 = (29 – 20) / 2 = 9/2 = 4.5 m / s2.

The time will be equal to:

t = (2 * h / a) ^ 0.5 = (2 * 4 / 4.5) ^ 0.5 = (8 / 4.5) ^ 0.5 = 1.7 ^ 0.5 = 1, 3 seconds.

Answer: The climb lasted 1.3 seconds.