A 0.02 cm liquid column balances the excess pressure inside a soap bubble of radius 7.5 mm. Determine the density of the liquid. Surface tension of soap solution `0.03 Nm^-1`.

Explanation

To solve the problem, we need to determine the density of the liquid that balances the excess pressure inside a soap bubble. We'll use the given information about the height of the liquid column, the radius of the soap bubble, and the surface tension of the soap solution.

### Step-by-Step Solution:

1. **Understand the Problem**: We need to find the density of the liquid (ρ) that balances the excess pressure inside a soap bubble. The excess pressure (ΔP) inside a soap bubble is given by the formula:
\[ \Delta P = \frac{8 \sigma}{R} \]
...