Question

Each of the following statements describes force acting. Which force is causing work to be done?
A. The weight of a book at rest on a table
B. The pull of a moving railway engines on its coaches
C. The tension in an elastic band wrapped around a parcel.
D. The push of a person’s feet when standing on the floor.

Answer 1

Hint: A force in physics is any influence that, when unopposed, changes the motion of an object. A force can cause a mass object's velocity to alter, causing it to accelerate. Intuitively, force can be described as a push or a pull. A force is a vector quantity since it has both magnitude and direction.

Complete answer:
When a force works on an object to cause it to move, it is said that work was done on the thing. Work consists of three essential components: force, displacement, and cause. There must be a displacement and the force must cause the displacement for a force to qualify as having done work on an object.

If a force is applied to a body but there is no displacement, we cannot state that work has been completed.As a result of the preceding knowledge, it is possible to conclude that in order for work to be completed, there must be a motion of the body in the direction of the applied force.

So, the correct option is (B).

Note: When the force applied to an object is larger than the opposing force applied to that object, spatial displacement occurs (distance). Remember that one of Newton's laws states that there is an equal but opposite force for every force. We are also lucky in that we believe in energy conservation, which means that one side of the equation must equal the other. It is a zero-sum theory.