Pressure due to uneven water distribution in connecting pipe

[rwooduk]

Homework Statement

Homework Equations

The Attempt at a Solution

Im confused by this question, just looking at the diagram without any maths you can see what would happen. C and D would want to reach equilibrium and be at the same level so the pressure down on D would be the difference in heights of the fluid. ie. 12 h times p g. but the equation says 15 not sure how they arrived at that? could anyone here help please? i am trying to get the formula given

 

[TSny]

The 15h in the answer relates the pressure at D to atmospheric pressure. You are right that the pressure at D is related to the pressure at C by 12h.

 

[rwooduk]

The 15h in the answer relates the pressure at D to atmospheric pressure. You are right that the pressure at D is related to the pressure at C by 12h.

Many thanks for the reply! ok so the pressure at D, is the atmospheric pressure minus (because it acts in the opposite direction) the pressure due to unequilibrium? I still can't see where the 15 comes from, please could you expand a little? thanks again

 

[TSny]

See if you can work your way through the system point by point. Find P at A, then B, then C, then D. (You can probably skip A.)

 

[rwooduk]

See if you can work your way through the system point by point. Find P at A, then B, then C, then D. (You can probably skip A.)

ok will try that, thanks again!