Mathematics 9709 · AS & A Level · Energy, work and power
Energy, work and power — practice question
A toy railway locomotive, with mass $0.8\text{ kg}$, is pulling a truck of mass $0.4\text{ kg}$ along a straight horizontal track at a steady speed of $2\text{ m s}^{-1}$. The locomotive experiences a constant resistive force of magnitude $0.2\text{ N}$, whereas the truck has no resistive force acting on it. The locomotive and the truck are joined by a light rigid horizontal coupling.
(a)[1]
State the value of the tension in the coupling.
(b)[1]
Find the power output of the locomotive’s engine.
(c)[5]
The locomotive’s engine power is now $1.2\text{ W}$. Find the size of the tension in the coupling at the instant the locomotive starts to accelerate.
Worked solution & mark scheme
This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: “The tension is zero.” …