A disc of mass `M` and radius `r` is rotating with an angular velocity `omega`. If gently, two masses `m` each are placed at a distance `r//2` on either side of the axis of rotation, what will be the new angular velocity ?

Explanation

To solve the problem, we need to apply the principle of conservation of angular momentum. Here’s a step-by-step breakdown of the solution:

### Step 1: Understand the Initial Conditions
We have a disc of mass \( M \) and radius \( r \) rotating with an initial angular velocity \( \omega \). The moment of inertia \( I \) of the disc about its center is given by:
\[ I_{\text{disc}} = \frac{1}{2} M r^2 \]

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