Question

a box of mass 50kg is pulled up from the hold of a ship with an acceleration of 1m/s2 by a vertical rope attached to it.Find the tension in the rope what is the tension in the rope when the box moves up with a uniform velocity of 1m/s

Answer 1

A box of mass 50kg is pulled up from the hold of a ship with an acceleration of 1m/s2 by a vertical rope attached to it. Find the tension in the rope what is the tension in the rope when the box moves up with a uniform velocity of 1m/s.

Second Newton's law:

$$T - F _ {g} = M a$$ $$T = F _ {g} + M a = M g + M a = M (g + a)$$ $$T = 50kg * (9.8m/s^2 + 1m/s^2) = 540N$$

If the box moves with uniform velocity, the rope tension is equal to the box's weight at rest:

$$T = Mg = 50kg * 9.8m/s^2 = 490N$$