Question

A man having a box on his head, climbs up a slope and another man having an identical box walks the same distance on a levelled road. Who does more work against the force of gravity and why?

Answer 1

Step 1:Given data

A Man climbs up a slope,

The another man travel the same distance on a levelled road.

Step 2: Work done for man climbs up slope
The work done carried out by the man will be,
$W=F\times S\times \cos \theta$
Where in most cases $\cos \theta$ becomes $1$, so the force is in the same direction as displacement,
So, $\theta =0$.

Therefore, the work done by man climbing up slope is $W=F\times S$.

Step 3: Work done man travel on a levelled road.
Here the work done is, $work=0$ as the walking is along the levelled road so he does no work against gravity.
The displacement of load is normal to the direction of the force of gravity.
Therefore,
$W=F\times S\times \cos \theta$
Where, $\theta =90°$
Thus, $\cos \theta =0$and

$work=F\times S\times 0=0$
Hence the man having a box on his head climbing up a slope does more work because the work done by the man walking on a leveled road is zero.