Practicing Success

Target Exam

CUET

Subject

Physics

Chapter

Work Power Energy

Question:

Assertion : When the force retards the motion of a body, the work done is zero.

Reason :  Work done depends on angle between force and displacement.

Which of the following option(s) is correct ?

Options:

Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion

Assertion is correct but Reason is incorrect

Reason is correct but Assertion is incorrect

Correct Answer:

Reason is correct but Assertion is incorrect

Explanation:
  1. When the force retards the motion of a body, the work done is NOT zero but negative as the force is still in action and the body covers a finite distance before coming to rest.
  2. Work done is given by : \(W = \vec{F}.\vec{S} = FS \cos {\theta}\). Thus, the work done depends upon the angle between the force and displacement.