In a fly wheel, most of the mass is concentrated at the rim ? Explain why.

Explanation

### Step-by-Step Solution

1. **Understanding the Flywheel**: A flywheel is a mechanical device that stores rotational energy. It is commonly used in transport vehicles to provide smooth motion and to help maintain a constant speed.

2. **Mass Distribution in a Flywheel**: In a flywheel, most of the mass is concentrated at the rim (the outer edge). This design is intentional and serves a specific purpose.

3. **Moment of Inertia**: The moment of inertia (I) of a body is a measure of how difficult it is to change its rotational motion. For a flywheel, the moment of inertia is calculated using the formula:
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