## College Physics (4th Edition)

We can find the height $h_f$ of the fluid that would have the same gauge pressure as 12 mm Hg: $\rho_f~g~h_f = \rho_m~g~h_m$ $h_f = \frac{\rho_m~h_m}{\rho_f}$ $h_f = \frac{(13.6~g/cm^3)~(12~mm)}{1.05~g/cm^3}$ $h_f = 155~mm = 15.5~cm$ The IV bag must be hung at least 15.5 cm above the vein.