Exam-style question
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A hoop of mass 3 kg and radius 0.5 m is rotating about its central axis. What is its moment of inertia?.
- A.0.75 kg·m²
- B.1.5 kg·m²
- C.3 kg·m²
- D.7.5 kg·m²
Model answer
What a good answer should say
- 0.75 kg·m²
Explanation
Why this works
The formula for the moment of inertia of a hoop is I = m * r². Substituting the values, I = 3 kg * (0.5 m)² = 3 * 0.25 = 0.75 kg·m².
Thus, the moment of inertia is 0.75 kg·m².
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