Calculate the moment of inertia of a ring of mass `2kg` and radius `2cm` about an axis passing through its centre and perpendicular to its surface.

Explanation

To calculate the moment of inertia of a ring about an axis passing through its center and perpendicular to its surface, we can follow these steps:

### Step-by-Step Solution

1. **Identify the formula for the moment of inertia of a ring**:
The moment of inertia \( I \) of a ring about an axis passing through its center and perpendicular to its surface is given by the formula:
\[
I = m r^2
...