A wheel of perimeter 220 cm rolls on a level road at a speed of 9 km/h. How many revolutions does the wheel make per second?

Explanation

To solve the problem of how many revolutions a wheel makes per second, we can follow these steps:

### Step 1: Convert the speed from km/h to m/s
The speed given is 9 km/h. To convert this to meters per second (m/s), we use the conversion factor:
\[ \text{Speed (m/s)} = \text{Speed (km/h)} \times \frac{5}{18} \]
Calculating this gives:
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