U-shaped tube- how far does the mercury rise when water is poured into one side?

[kalisious]

U-shaped tube-- how far does the mercury rise when water is poured into one side?

Homework Statement

A U-shaped tube containing mercury is open to the air on both ends. Water is poured into one arm until the water column is 15.0 cm deep. How far upward from the initial position does the mercury in the right arm rise?

Homework Equations

P = P₀+density(gh)
P = P₀+(density*h)(g)

The Attempt at a Solution

I am not sure how to go about this solution!

 

[willem2]

The pressure from the water column must match the pressure from the difference in the mercury columns. Once you know this difference it's easy to find how much the mercury in the right arm has risen.