Question

A sea diver at depth of 45 m exhales a bubble of air that is 1.0 cm in radius. Assuming the ideal behaviour, find out radius of this bubble as it breaks at the surface of water?

• A. 1.75 cm
• B. 1.50 cm
• C. 1.25 cm
• D. 0.75 cm

Answer 1

The correct option is A

1.75 cm

$P_1{V}_1=P_2{V}_2$ $(p=hdg)$

$(P_{air}+P_{H_{2}O})V_1=P_{air}{V}_2$

$(76\times 13.6\times g+4500\times 1\times g)\frac{4}{3}\pi \left(1^3\right)$

$=76\times 13.6\times g\times \frac{4}{3}\pi r^3$

$\Rightarrow r^3=5.35\Rightarrow r=1.75cm$