Question

In which situation is no work done?

Answer 1

Hint: In order to answer this question, we will discuss the situation when there is no work done, and then we will also explain the situation numerically in brief. And then we will discuss more about the work done or not, when some force is applied.

Complete answer:
When a force is applied to an item, it causes the item to move, and the force performs work. There is no work done if the applied force does not move the item.
We can also say the given statement as, when is the work done said to be zero? So, when force and displacement are perpendicular to each other or when either force or displacement is zero, the work done is said to be zero. When we walk with a thing in our hands, the force acts in a downward direction, whereas displacement acts in a forward direction.
Work is defined in physics as the product of the applied force and the displacement of the object. We are asked to explain a condition in which no work is being done as well as a condition in which work is being done.
Therefore, work is zero, when:
$\cos \theta $ is zero,
or $\theta = \dfrac{\pi }{2}$ .
When a force moves an object in a positive direction, the work done is positive. The motion of a ball falling towards the earth, with the displacement of the ball in the direction of gravity, is an example of this type of work.

Note:
When a force is applied to an object, it causes it to move. This is referred to as work. The wall will not move if you exert force on it. Force is imparted to it here, yet no displacement occurs. As a result, even though a force is applied to it, work is zero.