All Problems

Liquids. Capillary effects

Problem 2.160

Find the capillary pressure (a) in mercury droplets of diameter \(d=1.5 \mu \mathrm{m}\) (b) inside a soap bubble of diameter \(d=3.0 \mathrm{~mm}\) if the surface tension of the soap water solution is \(\alpha=45 \mathrm{mN} / \mathrm{m}\).

Reveal Answer
 (a) Δp=4α/d=13 atm;  (b) Δp=8α/d=1.2103 atm\text { (a) } \Delta p=4 \alpha / d=13 \text { atm; } \text { (b) } \Delta p=8 \alpha / d=1.2 \cdot 10^{-3} \mathrm{~atm}