Mathematics 9709 · AS & A Level · Energy, work and power
Energy, work and power — practice question
A particle with mass $18\,\text{kg}$ is placed on a plane inclined at an angle of $30^\circ$ to the horizontal. It is projected along the line of greatest slope of the plane with speed $20\,\text{m s}^{-1}$.
(i)[4]
If the plane is smooth, use an energy method to determine the distance the particle travels up the plane before it is momentarily at rest.
(ii)[8]
If instead the plane is rough and the coefficient of friction between the particle and the plane is $0.25$, determine the speed of the particle as it returns to its starting point.
Worked solution & mark scheme
This 12-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Identifies the relevant energy terms: PE gain $= 18g\sin30^\circ$ or KE loss $= \tfrac12 \times 18 \times 20^2$” …