# Manometer Equation Error

This is the question I was trying to solve.

This was the solution offered by the book.

When I was solving it, I applied the manometer equation at the initial level, but I got a different answer.

I can't figure out where I'm going wrong... any help is appreciated.

• The pressures at points 1 and 2 are equal. Commented Oct 29, 2019 at 14:03
• @ChetMiller isn't that the case for pressures at the initial level too? Commented Oct 29, 2019 at 17:16
• Yes, that is the case for the pressures at the initial level too. But that doesn't seem relevant to the analysis of the final state. Commented Oct 29, 2019 at 17:44
• @ChetMiller I'm sorry, I'm confused. Can you tell what is wrong with the way I approached the problem? Is it incorrect to apply the equal pressure concept at the initial level of liquids, in the final state? Commented Oct 29, 2019 at 18:58
• The initial state is not relevant. What is wrong with the way you approached the problem is that the pressure at point 1 is not equal to $P_0+\rho g (27.2-x)$. In the final state shown in the diagram, the pressure at point 1 is $P_0+\rho g (27.2)$, where $P_0$ is the pressure at the top of the column. Commented Oct 29, 2019 at 19:50