A car is moving at a speed of `72 km//h`. The diamter of its whells is `0.5 m`. If the wheels are stopped in `20` rotations by applying brakes, calcualte the angular retardation produced by the brakes.

Explanation

To solve the problem step by step, we will follow these calculations:

### Step 1: Convert the speed from km/h to m/s
The speed of the car is given as `72 km/h`. We need to convert this speed into meters per second (m/s).

\[ \text{Speed in m/s} = \frac{72 \text{ km/h} \times 1000 \text{ m/km}}{3600 \text{ s/h}} = \frac{72000}{3600} = 20 \text{ m/s} \]
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