A worker moves a heavy crate up a smooth plank long that is inclined at to the horizontal
PHYSICS · Multi-part · CBSE · Physics · Work and Energy · Work and Energy
Problem
A worker moves a heavy crate up a smooth plank 6m long that is inclined at 25∘ to the horizontal. The worker pulls on a rope attached to the crate such that the rope makes an angle of 10∘ above the surface of the plank (that is, 10∘ to the line of motion of the crate up the plank).
(i) If the work done by the force exerted through the rope in moving the crate the full length of the plank is 1200J, calculate the magnitude of the force applied.
(ii) Suppose the worker now keeps the rope exactly along the surface of the plank while exerting the same magnitude of force as in part (i). How much work would the force do in moving the crate the same 6m up the plank? State whether this work is greater than, less than, or equal to 1200J and give a reason for your answer.