A raindrop of radius 0.2 mm falls through air: If the viscosity of air is 18 `xx 10^(-6)` Pl, find the viscous drag acting on the drop when its speed is 1 m `s^(-1)`.

Explanation

To solve the problem of finding the viscous drag acting on a raindrop falling through air, we will use Stokes' law. The steps are as follows:

### Step 1: Convert the radius from millimeters to meters
The radius of the raindrop is given as 0.2 mm. We need to convert this to meters for our calculations.

\[ r = 0.2 \, \text{mm} = 0.2 \times 10^{-3} \, \text{m} = 0.0002 \, \text{m} \]
...