Question

In which one of the following cases is work done the maximum ?

• A. Mohan pushes against a wall for $30minutes$
• B. Mohan pushes a bicycle which moves through a distance of $1.5m$
• C. Mohan pushes a truck which does not move at all
• D. Mohan stands in the centre of his room

Answer 1

Answer: (B)

Mohan pushes a bicycle which moves through a distance of $1.5m$

Work done is defined as $W=Fs\cos \theta$, where $F$ is the force applied, $s$ is the displacement and $\theta$ is the angle between force applied and displacement.

In cases A, C and D there is no displacement($s$) taking place.
So, $W=Fs\cos \theta =0$ (as $s=0$)

In case B: $s=1.5m$ so, Mohan does some work.

Hence, work done in case B is maximum.

So, option B is correct.