A warehouse worker exerts a constant 150N force on a crate while dragging it 4.0m across a concrete floor. The force is applied at 30∘ below the horizontal.
Neglect any forces except the worker’s pull for the purpose of this calculation.
(a) Calculate the work done on the crate by the worker’s force, including the proper sign and units.
(b) Briefly explain the physical significance of the sign of your answer in part (a).