# Sheet nozzle by mikesanye

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```									Faculty of Engineering
Engineering Physics I Course
Lecturer: Dr. Ahmed Emara
T.A: Eng. Sherif Omar
Sheet (3)
Fluid mechanics

1. Assuming that the density of ocean water is 1024 kg/m3 and the air above exerts a
pressure of 101.3kpa.
a- Calculate the absolute pressure at an ocean depth of 1000m.
b- At this depth, what force must the frame around a circular submarine port
hole having a diameter of 30 cm exert to counterbalance the force exerted
by water.

2. The tank shown in figure is filled with water 2m deep. At the bottom of one
sidewall is a rectangular hatch 1m high and 2m wide that is hinged at the top of
the hatch. Determine the force the water causes on the hatch.

3. Mercury is poured into a U-tube as in figure (a). The left arm of the tube has
cross-sectional area A1 of 10.0 cm2, and the right arm has a Cross-sectional area
A2 of 5.00 cm2. One hundred grams of water are then poured into the right arm as
in figure (b).
(a) Determine the length of the water column in the right arm of the U-tube.
(b) Given that the density of mercury is 13.6 g/cm3, what distance h does the
mercury rise in the left arm?

Spring 2009                                                                 Sheet 3 – P.1
Faculty of Engineering
Engineering Physics I Course
Lecturer: Dr. Ahmed Emara
T.A: Eng. Sherif Omar
4. Archimedes supposedly was asked to determine whether a crown made for the
king consisted of pure gold. According to the legend, Archimedes solved this
problem by weighting the crown first in air and then in water as shown in figure.
Suppose the scale read 7.84N when the crown was in air and 6.84N when the
crown was in water. Given that the density of water is 1000 kg/m3 and the density
of gold is 19.3103 kg/m3. What should Archimedes have told the king?

5. The Figure shows a stream of water in steady flow from a kitchen faucet. At the
faucet the diameter of the stream is 0.96 cm. The stream fills a 125 cm3 container
in 16.3 s. Find the diameter of the stream 13 cm below the opening of the faucet.

Spring 2009                                                                   Sheet 3 – P.2
Faculty of Engineering
Engineering Physics I Course
Lecturer: Dr. Ahmed Emara
T.A: Eng. Sherif Omar
6. A village maintains a large tank with an open top, containing water for
emergencies. The water can drain from the tank through a hose of diameter 6.6
cm. The hose ends with a nozzle of diameter 2.2 cm. A rubber stopper is inserted
into the nozzle. The water level in the tank is kept 7.5 m above the nozzle.
(a) Calculate the friction force exerted by the nozzle on the stopper.
(b) The stopper is removed. What mass of water flows from the nozzle in 2 h?
(c) Calculate the gauge pressure of the flowing water in the hose just behind the
nozzle.

7. The horizontal constricted pipe illustrated in figure, known as a Venturi tube, can
be used to measure the flow speed of an incompressible fluid. If the difference in
pressure is P1–P2=21 kPa, find the fluid flow rate in cubic meters per second,
given that the radius of the outlet tube is 1 cm, the radius of the inlet tube is 2 cm,
and the fluid is gasoline ( ρ=700 kg/m3 ).

Home work: This H.W is due at the beginning of the next tutorial.

1- Water flows through a fire hose of diameter 6.35 cm at a rate of 0.012 m3/s. The
fire hose ends in a nozzle of inner diameter 2.2 cm. What is the speed with which
the water exits the nozzle?

2- A large storage tank, open at the top and filled with water, develops a small hole
in its side at a point 16 m below the water level. If the rate of flow from the leak is
2.5×10-3 m3/min, determine:
(a) The speed at which the water leaves the hole,
(b) The diameter of the hole.

Spring 2009                                                                      Sheet 3 – P.3
Faculty of Engineering
Engineering Physics I Course
Lecturer: Dr. Ahmed Emara
T.A: Eng. Sherif Omar
3- Water is forced out of a fire extinguisher by air pressure, as shown in figure. How
much gauge air pressure (above atmospheric) in the tank is required for the water
jet to have a speed of 30m/s when the water level in the tank is 0.5 m below the
nozzle?

Spring 2009                                                                  Sheet 3 – P.4

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