A boy pushes a lawn roller along a straight horizontal path by applying a constant…
PHYSICS · Multi-part · CBSE · Physics · Work and Energy · Work and Energy
Problem
A boy pushes a lawn roller along a straight horizontal path by applying a constant force of magnitude F at an angle of 60∘ above the horizontal. The roller moves a distance s along the path.
(i) State whether the work done by the boy on the roller is positive, negative or zero.
(ii) Justify your answer in part (i) with reference to the angle between the force and the displacement.
(iii) The surface exerts a frictional force opposite to the motion. What is the sign of the work done by the frictional force? Explain.