A gasoline line is connected to a pressure gage through a double-U manometer, as shown. If the reading of the pressure gage is 260 kPa, determine the gage pressure of the gasoline line. Assume the density of air to be 1.225 kg/m3.

E9

Atmospheric pressure at this location is 102.0 kPa and fluid temperature is presently 30°C. Oil (sg = 0.90) C Water 125 mm 475 mm 250 JU mm 50 mm Mercury (sg = 13.54) Figure 1: Compound manometer (note: sg = specific gravity)

The Venturi meter shown in the sketch below, contracts the flow down to one quarter of its original area. Cold air at 0 deg C flows in the pipe through the Venturi meter. The velocity of the air upstream of the Venturi meter  is equal to 40 ft/s and the pressure at the same point is equal to 30 psia. What is the manometer reading if the fluid of the manometer is water with density 1000 kg/m3 .  Assume that the air behaves as an ideal gas with molecular weight equal to Mw=29 kg/kmol and constant density evaluated at upstream conditions. Use Bernoulli's equation for your calculations.  please respond asap!