(a) A uniform 2.00 kg disk of radius 0.300 m can rotate around its central axis like a merry-go-round. Beginning from rest at time t = 0, it undergoes a constant angular acceleration of `30.0rad//s^(2)`. When is the rotational kinetic energy equal to 2000 J? (b) Repeat the calculation but substitute a ring of the same mass and radius and assume that the spokes have negligible mass.

Explanation

To solve the problem step by step, we will break it down into two parts: (a) for the disk and (b) for the ring.

### Part (a): Uniform Disk

1. **Identify Given Values**:
- Mass (m) = 2.00 kg
- Radius (r) = 0.300 m
- Angular acceleration (α) = 30.0 rad/s²
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