A mason drags a bag of cement across a horizontal floor by pulling on a rope that makes an unknown angle θ with the direction of motion.
(i) The bag is pulled a distance of 8m by a constant force of 40N, and the work done by this force is 250J. Calculate the angle θ between the rope and the direction of motion.
(ii) The mason now holds the rope so that the angle becomes 120∘ while keeping the magnitude of the force and the displacement the same. Calculate the work done in this case and state whether it is positive, negative, or zero, giving a brief reason.