posted by Zuen-Lee .
The cross-sectional area of the U-tube shown below is uniform and is equal to one square centimeter (1.00cm^2). One end is open to the atmosphere. Atmosphere pressure may be taken as P1=1.01 * 10^5 Pa. The other end of the U-tube is connected to a pipe in which a constant gas pressure of P2=1.25 atmospheres is maintained. The U-tube contains a liquid which has a density of 1.0*10^4kg/m^3.
QUESTION: What the second liquid still in the arm that is open to the atmosphere, the pressure p2 is now reduced until it is equal to atmospheric pressure. What now is the difference (if any) between the liquid levels in the two arms of the U-tube?