A particle of mass m moves in a circle of radius r with constant speed v. What is the net work done by the centripetal force during one complete revolution?
Answer and explanation
Correct answer: C. 0 J
- Step 1: Work is W = F d cos(theta). Step 2. The centripetal force is always directed toward the center, perpendicular to the tangential displacement (theta = 90°). Step 3. cos(90°) = 0, so work done is identically zero. Kinetic energy remains constant throughout. Answer: 0 J. Why not the others: Centripetal force changes the direction of velocity, not its magnitude.
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