Question

By sucking through a straw, a student can reduce the pressure in his lungs to $750mm$ of Hg (density = $13.6gm/{cm}^3$). Using the straw, he can drink water from a glass upto a maximum depth of:

• A. $10cm$
• B. $75cm$
• C. $13.6cm$
• D. $1.36cm$

Answer 1

The correct option is C $13.6cm$

Pressure difference created $=10mm$ of Hg
This must be equal to the pressure of water column being created in the straw. If height of water column be $h$

$h\rho g=\frac{10}{10}\times 13.6g$

$hg\times 1=13.6g$

$h=13.6cm$