Answer:
a) [tex]P=2450\ Pa[/tex]
b) [tex]\delta h=23.162\ cm[/tex]
Explanation:
Given:
height of water in one arm of the u-tube, [tex]h_w=25\ cm=0.25\ m[/tex]
a)
Gauge pressure at the water-mercury interface,:
[tex]P=\rho_w.g.h_w[/tex]
we've the density of the water [tex]=1000\ kg.m^{-3}[/tex]
[tex]P=1000\times 9.8\times 0.25[/tex]
[tex]P=2450\ Pa[/tex]
b)
Now the same pressure is balanced by the mercury column in the other arm of the tube:
[tex]\rho_w.g.h_w=\rho_m.g.h_m[/tex]
[tex]1000\times 9.8\times 0.25=13600\times 9.8\times h_m[/tex]
[tex]h_m=0.01838\ m=1.838\ cm[/tex]
Now the difference in the column is :
[tex]\delta h=h_w-h_m[/tex]
[tex]\delta h=25-1.838[/tex]
[tex]\delta h=23.162\ cm[/tex]