2.26 For an atmospheric pressure of 101 kPa (abs) determine
the heights of the fluid columns in barometers containing one
of the following liquids: (a) mercury, (b) water, and (c) ethyl alcohol.
Calculate the heights including the effect of vapor pressure
and compare the results with those obtained neglecting vapor pressure.
Do these results support the widespread use of mercury for
barometers? Why?
2.32 For the inclined-tube manometer of Fig. P2.32, the pressure
in pipe A is 4.1 kPa. The fluid in both pipes A and B is water, and
the gage fluid in the manometer has a specific gravity of 2.6. What
is the pressure in pipe B corresponding to the differential reading
shown?
2.56 A horizontal 2-m-diameter conduit is half filled with a liquid
(SG = 1.6) and is capped at both ends with plane vertical
surfaces. The air pressure in the conduit above the liquid surface
is 200 kPa. Determine the resultant force of the fluid acting on
one of the end caps, and locate this force relative to the bottom
of the conduit.
2.67 A gate having the cross section shown in Fig. 2.67
closes an opening 1.5 m wide and 1.2 m high in a water reservoir. The
gate weighs 2.5 kN, and its center of gravity is 0.3 m to the left of
AC and 0.6 m above BC. Determine the horizontal reaction that is
developed on the gate at C.
2.88 The homogeneous gate shown in Fig. P2.88 consists
of one quarter of a circular cylinder and is used to maintain a water
depth of 4 m. That is, when the water depth exceeds 4 m, the gate
opens slightly and lets the water flow under it. Determine the
weight of the gate per meter of length.
2.89 The concrete (specific weight = 23.6 kN/m3) seawall
of Fig. P2.89 has a curved surface and restrains seawater at a
depth of 7 m. The trace of the surface is a parabola as illustrated.
Determine the moment of the fluid force (per unit length) with respect
to an axis through the toe (point A).