(a) Define mechanical work done by a constant force. (b) A gardener pushes a lawn…
PHYSICS · Subjective · CBSE · Physics · Work, Energy and Power · Work, Energy and Power
Problem
(a) Define mechanical work done by a constant force.
(b) A gardener pushes a lawn roller by applying a constant horizontal force of magnitude 50N at an angle of 60∘ below the horizontal ground. The roller moves 20m along the ground in the forward direction. State, with reasons, whether the work done by the applied force is positive, negative or zero.
(c) The same force of 50N is now applied at 60∘ to the horizontal, but the roller is lifted vertically upward through 20m. Identify the sign (positive, negative or zero) of the work done in this case and justify your answer.