JEE Physics · Medium

Rigid Body Dynamics: Rolling on Incline MCQ

Solve this quality-checked JEE multiple-choice question, then review the correct answer and explanation.

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Rolling on InclineMediumQuestion 30321

Question

A solid sphere and a hollow sphere of same mass and radius roll down the same incline from rest. Which reaches the bottom first?
  1. A
    Hollow sphere
  2. B
    Solid sphere
    Correct
  3. C
    Both together
  4. D
    Depends on mass

Correct answer

Solid sphere

Explanation

Acceleration of rolling body: a = g sinθ/(1 + I/mR²). For solid sphere: I = 2mR²/5, so a = 5g sinθ/7. For hollow sphere: I = 2mR²/3, a = 3g sinθ/5. 5/7 > 3/5, so solid sphere has more acceleration and arrives first.