A student pushes a lawn-mower on a level ground by applying a constant horizontal force of
PHYSICS · Multi-part · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
A student pushes a lawn-mower on a level ground by applying a constant horizontal force of 200N. The mower moves with a steady speed of 1.5m/s.
(a) Calculate the power developed by the student while the mower is moving at this speed.
(b) The student now speeds up the mower to 3.0m/s while keeping the applied force the same. Determine the new power developed.
(c) Find the ratio of the power obtained in part (b) to that in part (a) and comment on how power depends on speed for the same applied force.