What is the gas pressure in the flask when the multiple Utub

What is the gas pressure in the flask when the multiple U-tube manometer indicates column heights as shown in the figure? P_atm = 0 sp gr Hg = 13.57

Solution

Let the pressure of gas is P_gas.

The pressure difference in a inclined u-tube manometer can be expressed as

W_m = Specific Gravity of Mercury = 13.57

W_w = Specific Gravity of Water = 1.00

P_gas- P_atm = W_m *10 - W_m * 30 + Ww* 10 + W_m * 20 - W_m * 80 sin 30

= [13.57 *10 - 13.57 *30 + 10+ 13.57*20 -13.57*80*sin30] /100

= 5.58 N/m²