MODEL: The pressure at any point in the fluid depends only on the depth of the
point and the density of the fluid above (equation 13.9, pg 442). We can
calculate the pressure at the bottom of the U-tube (at the junction of the two
fluids) by using either arm of the tube.

SETUP: On the left hand side, what are the appropriate
values of density and depth *d*? What are the values on the right hand side? Does the value of *P*_{0} matter?

SOLVE: Set the value of *P* at the bottom calculated in the left
hand tube equal
to the value calculated in the right hand tube.
© 1997 Susan M. Lea