Define Stoke’s law. Define and derive an expression for terminal velocity.

Explanation

### Step-by-Step Solution

**Step 1: Define Stoke's Law**

Stoke's Law states that the viscous force \( F_{\text{viscous}} \) acting on a spherical body of radius \( r \) moving with a velocity \( v \) in a fluid with viscosity \( \eta \) is given by the equation:

\[
F_{\text{viscous}} = 6 \pi \eta r v
...