Question:
Find the excess pressure inside
(a) a drop of mercury of radius $2 \mathrm{~mm}$
(b) soap bubble of radius $4 \mathrm{~mm}$ and
(c) An air bubble of radius $4 \mathrm{~mm}$ formed inside a tank of water.
Surface tension of mercury, soap solution and water are $0.465 \mathrm{~N} / \mathrm{m}, 0.03 \mathrm{~N} / \mathrm{m}$ and $0.076 \mathrm{~N} / \mathrm{m}$ respectively.
Solution:
