Mathematics 9709 · AS & A Level · Energy, work and power
Energy, work and power — practice question
A lorry with mass $15\,000\,\mathrm{kg}$ moves up a straight hill of length $1440\,\mathrm{m}$ from the bottom to the top at a steady speed of $15\,\mathrm{m\,s^{-1}}$. The summit is $16\,\mathrm{m}$ above the level of the foot of the hill. The resistance to motion is constant at $1800\,\mathrm{N}$.
(i)[4]
Find the work carried out by the driving force.
(ii)[3]
Once it reaches the top of the hill, the lorry travels along a straight horizontal road and passes point $P$ with speed $24\,\mathrm{m\,s^{-1}}$. The resistance to motion remains constant and is now $1600\,\mathrm{N}$. The work done by the lorry’s engine from the top of the hill to point $P$ is $5030\,\text{kJ}$. Find the distance from the top of the hill to the point $P$.
Worked solution & mark scheme
This 7-mark question has a full step-by-step worked solution and mark scheme.