(i)[1]
Find the amount of work done against friction.
(ii)[2]
Find how much the gravitational potential energy of the box changes.
(iii)[2]
Find the work done by the pulling force.
Mathematics 9709 · AS & A Level · Energy, work and power
Energy, work and power — practice question
A box with mass $25\,\text{kg}$ is dragged a distance of $36\,\text{m}$ up a rough plane that is inclined at $20^\circ$ to the horizontal, moving at constant speed. It travels along the line of greatest slope while a steady frictional force of $40\,\text{N}$ acts against it. The pulling force is parallel to the line of greatest slope.
Worked solution & mark scheme
This 5-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Work done against the resisting force: $WD = 40 \times 36 = 1440\text{ J}$” …
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