A child pulls a sledge across flat snow with a rope.
The rope is horizontal.
The child does 1.5 kJ of work pulling the sledge with a constant force of 60 N.
Calculate the distance the sledge moves.
During this time, the kinetic store of the sledge increases by 300 J.
Calculate the energy transferred to thermal stores.
Explain how the energy transferred to thermal stores could be reduced.
The child then pulls the sledge the same distance at the same constant speed across rougher snow.
Explain how the work done by the child changes.