Mathematics 9709 · AS & A Level · Energy, work and power
Energy, work and power — practice question
A car with mass $1400\,\text{kg}$ is moving uphill on a slope that makes an angle of $4^{\circ}$ to the horizontal. A constant resistive force of magnitude $1550\,\text{N}$ acts on the car.
(i)[4]
The car’s engine is delivering $30\,\text{kW}$. Find the car’s speed at the instant when its acceleration is $0.4\,\text{m s}^{-2}$.
(ii)[3]
The car’s greatest possible steady speed while going uphill is $40\,\text{m}\,\text{s}^{-1}$. Find the maximum power the engine can produce.
Worked solution & mark scheme
This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Uses Newton’s Second Law with four forces” …