During a heavy rain hailstones of average size 1.0 cm in diameter fall with an average speed of 20 m/s. Suppose 2000 hailstones strike every square meter of a `10mxx10m` roof perpendicularly in one second and assume that the hailstones do not rebound. Calculate the average force exerted by the falling hailstones on the roof. Density of a hailstone is `900 kg/m^3`

Explanation

To solve the problem, we need to calculate the average force exerted by the falling hailstones on the roof. We will do this step by step.

### Step 1: Calculate the radius of a hailstone
Given the diameter of a hailstone is 1.0 cm, we can find the radius (r) as follows:
\[ r = \frac{\text{diameter}}{2} = \frac{1.0 \, \text{cm}}{2} = 0.5 \, \text{cm} = 0.005 \, \text{m} \]

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