Situation $6-$ For the Venturi meter shown, the deflection of mercury in the differential gage is $14\mathrm{.}3$ in$.$ Consider no energy is lost between A and $B.$

$13.$ Determine the pressure head difference between A and $B$ in terms of water.

A$.,18\mathrm{.}5ft$

C$.,19\mathrm{.}5ft$

B$.,17\mathrm{.}5ft$

D$.20\mathrm{.}5ft$

$14.$ Determine the velocity at the $6"$ section in $f\frac{t}{s}.$