Single correct option
Consider the following statements:
1. Work done by the centripetal force in uniform circular motion is zero.
2. Work done by friction is always negative.
Which of the statements given above is/are correct?
1. Work done by the centripetal force in uniform circular motion is zero.
2. Work done by friction is always negative.
Which of the statements given above is/are correct?
- A. 1 only
- B. 2 only
- C. Both 1 and 2
- D. Neither 1 nor 2
Show answer and solution
Answer: (A) 1 only
Statement 1 is correct: the centripetal force is always perpendicular to the displacement, so W = Fd cosθ = 0. Statement 2 is wrong because friction can do positive work, for example static friction on a box placed on an accelerating truck pushes the box forward along its displacement. So only statement 1 is correct.
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