Mathematics 9709 · AS & A Level · Energy, work and power
Energy, work and power — practice question
A particle with mass $0.8\,\text{kg}$ travels down a rough inclined plane in the direction of steepest descent along $AB$. The length of $AB$ is $8\,\text{m}$. The particle leaves $A$ with speed $3\,\text{m s}^{-1}$ and has constant acceleration $2.5\,\text{m s}^{-2}$.
(i)[2]
Find the speed of the particle at the moment it reaches $B$.
(ii)[4]
Given that $7\,\text{J}$ of work is done against the frictional force as the particle moves from $A$ to $B$, find the angle of inclination of the plane.
(iii)[3]
Find the work done by the frictional force during the particle’s motion from $A$ to $X$.
Worked solution & mark scheme
This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: “By using $v^2 = u^2 + 2as$” …