Question

Which of the following does not possess the ability to do work not because of motion?
A. A sparrow flying in the sky
B. A sparrow moving slowly on the ground
C. A sparrow in the nest on a tree
D. A squirrel going up a tree

Answer 1

Hint: Work is done by a force if the application of force produces a displacement on the body on which it is exerted. In the given options, work is done only when there is some displacement taking place.

Complete step by step answer:
The work done by a force can be defined as the product of force applied on a body and the corresponding displacement produced in the body. In other words, we can say that whenever a displacement is produced in a body on the application of a force, only then work is done by that body. Otherwise, if there is no displacement on the application of a force then no work is done.
In the given options, we have a squirrel and a sparrow which are under the influence of the gravitational force of attraction. They can do work in this field only if they show some movement.
A sparrow flying in the sky or moving slowly only the ground and a squirrel moving up a tree are doing work in the gravitational force of earth because there is movement or displacement taking place in this case. But a sparrow in the nest on a tree is not doing any work because there is no displacement taking place in this case.

So, the correct answer is “Option C”.

Note: Work done by a body is directly related to the energy stored in that body. A sparrow moving slowly on ground does less amount of work as compared to a sparrow flying in the sky and a squirrel going up a tree.