A body weighing 100 kg, suspended on a rope, moves up and in 4 seconds reaches a speed of 6 m / s

A body weighing 100 kg, suspended on a rope, moves up and in 4 seconds reaches a speed of 6 m / s from the beginning of the ascent. Determine the elastic strength of the rope.

To determine the elastic force of the rope used, we project all the acting forces onto the OU axis: m * a = T – Ft, from where we express: T = m * a + Ft = m * V / t + m * g = m * (V / t + g).
Constants and variables: m is the mass of the body suspended on the rope (m = 100 kg); V is the achieved speed (V = 6 m / s); t is the duration of the rise (t = 4 s); g – acceleration due to gravity (g ≈ 10 m / s2).
Calculation: T = m * (V / t + g) = 100 * (6/4 + 10) = 1.15 * 10 ^ 3 H = 1.15 kN.
Answer: The elastic force of the rope used is 1.15 kN.