Answer
a) The higher pressure air outside the straw pushes the water upward through the straw, overcoming the force of gravity.
b) $h=10.3m$
Work Step by Step
(a) When you sip water through a straw, your lungs first expand to create a low-pressure area of air in your mouth. This creates a pressure difference between the air in your mouth and outside the straw. The higher pressure air outside the straw pushes the water upward through the straw, overcoming the force of gravity.
(b) We know that
$h=\frac{P_{at}}{\rho g}$
We plug in the known values to obtain:
$h=\frac{1.01\times 10^5}{(1000)(9.81)}$
$h=10.3m$
