Question

Look at the activities listed below. Reason out whether or not work is done in the light of your understanding of the term 'work'.

An engine is pulling a train.

Answer 1

1. Work is said to be done when there is a displacement in the direction of applied force.
2. If force and displacement are perpendicular to each other then the work is considered zero.
   Mathematically $$\begin{gathered} \mathrm{W}=\mathrm{F}.\mathrm{X}.\mathrm{Cos\theta } \\ \mathrm{Where}\mathrm{W}\mathrm{is}\mathrm{work}\mathrm{done},\mathrm{F}\mathrm{is}\mathrm{force}\mathrm{X}\mathrm{is}\mathrm{displacement} \\ \mathrm{\theta }\mathrm{is}\mathrm{angle}\mathrm{through}\mathrm{which}\mathrm{force}\mathrm{is}\mathrm{applied}\mathrm{on}\mathrm{body}\mathrm{which}\mathrm{has}\mathrm{displaced}. \end{gathered}$$
3. When the engine is pulling the train, a force is being applied and there is a displacement for the train.
4. The displacement is in the same direction as the applied force, so work is said to be done.

So the work is said to be done by the engine.