Question

In which case work is done and why?

A porter carrying a load on his head walking along a level road.

Answer 1

• Analyzing problem:

When a porter is carrying a load on his head walking along a level road:

1. Force is applied i.e. equal to the weight of the load.
2. Displacement is in the direction perpendicular to the force applied.

• The formula of work done:

W=F d cos∅

where F = force applied to the object

d =displacement of the object

and ∅ = angle between the force and the displacement.

• Conclusion:

In the case of a porter carrying a load on his head walking along a level road, we have force as well as displacement but as they are at the right angle i.e., at${90}^o$, the work will not be done.

• Answer:

In this case, work is not done since the displacement and force are perpendicular to each other.