Question

A uniform tube 96cm long sealed at end, is lowered vertically with its
open end downwards into mercury until the length of the enclosed air
column is 84cm. with the aid of a diagram, find the depth of immersion of
the tube in the mercury if the atmospheric pressure is 77cm of mercury

Answer 1

$p_0V_0/T_0=pV/T\to p=p_0V_0/V$ ( $T_0=T$ )

$p=p_0V_0/V=p_0h_0A/(hA)\to p=p_0h_0/h=77\cdot96/84=88\ (cm\ of\ mercury)$

$\Delta h=(88-77)+(96-84)=11+12=23\ (cm)$ . Answer