Civil - Mechanics Of Fluids - Fluid Properties And Fluid Statics
1.What
are the gauge pressure and absolute pressure at a point 3 m below the free
surface of a liquid having a density of 1.53x10^{3} kg/m^{3} if
the atmospheric pressure is equivalent to 750 mm of mercury? The specific
gravity of mercury is 13.6 and density of water is 1000 kg/m^{3}.
2.Figure
shows a conical vessel having its outlet at A to which a U-tube manometer is
connected. The reading of the manometer given in the figure shows when the
vessel is empty. Find the reading of the manometer when the vessel is
completely filled with water.
3.Determine
the total pressure on a circular plate of diameter 1.5 m which is placed
vertically in water in such a way that the center of the plate is 3 m below the
free surface of water. Find the position of centre of pressure also.
4.A
vertical sluice gate is used to cover an opening in a dam wide and 1.2 m high. On the upstream of the
gate, the liquid of Sp.gr 1.45 lies upto a height of 1.5 m above the top of the
gate, whereas on the downstream side the water is available upto a height
touching the top of the gate. Find the resultant force acting on the gate and
position of centre of pressure. Find also the force acting horizontally at the
top of the gate which is capable of opening it. Assume that the gate is hinged
at the bottom.
5.A
block of wood of specific gravity 0.7 floats in water. Determine the
meta-centric height of the block if its size is 2 m x 1 m x 0.8 m.
6.Calculate
the dynamic viscosity of oil which is used for lubrication between a square
plate of size 0.8 mx0.8 m and an inclined angle of inclination 30 as shown in
figure. The weight of the square plate is 300 N and it slides down the inclined
plane with a uniform velocity of 0.3 m/s. The thickness of the oil film is 1.5
mm.
7.Find
the kinematic viscosity of an oil having density 981 kg/m. The shear stress at
a point in oil is 0.2452 N/m and velocity gradient at that point is 0.2 per
second.
8.The
dynamic viscosity of oil used for lubrication between a shaft and sleeve is 6
poise. The shaft is of diameter 0.4 m and rotates at 190 rpm. Calculate the
power lost in the bearing for a sleeve length of 90 mm. The thickness of the
oil film is 1.5 mm.
9.If
the velocity profile of a fluid over a plate is a parabolic with the vertex 20
cm from the plate, where the velocity is 120 cm/sec. calculate the velocity
gradients and shear stresses at a distance of 0, 10, 20 cm from the plate, if
the viscosity of the fluid is 8.5 poise.
10.
What is the bulk modulus of elasticity of a liquid which is compressed in a
cylinder from a volume of 0.0125 m^{3} at 80 N/cm^{2} pressure
to a volume of 0.0124 m^{3} at 150 N/cm^{2} pressure?
11.The
pressure outside the droplet of water of diameter 0.04 mm is 10.32 N/cm^{2}
(atmospheric pressure). Calculate the pressure within the droplet if surface
tension is given as 0.0725 N/m of water.
12.Calculate
the capillary rise in a glass tube of 2.5 mm diameter when immersed vertically
in (a) water and (b) mercury. Take surface tension is 0.0725 N/m for water and
0.52 N/m for mercury in contact with air. The specific gravity for mercury is
given as 13.6 and angle of contact is 130 o .
13.Find out the minimum size of glass tube that can be used to measure water level if the capillary rise in the tube is to be restricted to 2 mm. Consider surface tension of water in contact with air as 0.073575 N/m.