Fluid Mechanic I Exam-1
Name:
1. A system filled with a liquid is shown below. On the left there is a piston in a tube of cross-sectional
area A1 with a force F1 applied to it, and on the right there is a piston in a tube of cross-sectional area
A2 that is twice that of A1 and a force F2. The pistons are weightless. The two fluid levels are the same.
The relation between the force F2 and F1 is:
A.
B.
C.
D.
E.
F2 = F1
F2 = 2F1
F2 = F1/2
F2 = 4F1
F2 = F1/4
2. In Fluid Mechanics, the shearing strain rate
A.
1
𝑇𝑇
B.
𝐿𝐿
𝑇𝑇
C.
𝑇𝑇
𝐿𝐿
𝑑𝑑𝑑𝑑
𝑑𝑑𝑑𝑑
for a Newtonian fluid has dimensions of (𝑢𝑢 is velocity):
D.
𝐿𝐿2
𝑇𝑇
3. A tank is filled with a liquid, and the surface is exposed to the atmosphere. Which of the following
accurately represents the gage pressure distribution on the right-hand side of the tank?
4. For a fluid element in motion, the forces acting on the element are:
a) Gravity, shear, and normal forces
b) Gravity and shear forces
c) Gravity and normal forces
d) Normal and shear forces
The stagnation pressure for a fluid is
a)
b)
c)
d)
The pressure due to the velocity of the fluid
Not defined unless the fluid is moving
The sum of the static and dynamic pressure
Thermodynamic pressure
Fluid Mechanic I Exam-1
Name:
5. Explain what “non-slip boundary condition” is.
6. If 𝑙𝑙 is a distance, V is a velocity, determine the dimensions of 𝑎𝑎, G, and 𝛽𝛽, which appear in the
dimensionally homogeneous equation.
𝑙𝑙 = 𝑉𝑉𝑉𝑉 + 𝐺𝐺(3 − 𝛽𝛽)
7. The water level in an open standpipe is 80 ft above the ground. What is the static pressure at a fire
hydrant that is connected to the standpipe and located at ground level?
8. An irregularly shaped piece of a solid material weighs 8.0 lb in air and 6.0 lb when completely
submerged in water. Determine the density of the material.
Fluid Mechanic I Exam-1
Name:
9. 10-kg block slides down a smooth inclined surface as shown in the figure below. Determine the
terminal velocity of the block if the 0.1-mm gap between the block and the surface contains water.
Assume the velocity distribution in the gap is linear, and the area of the block in contact with the oil
is 0.1 m2.
10. Water, oil, and an unknown fluid are contained in the vertical tubes shown in the figure below.
Determine the density of the unknown fluid.
Fluid Mechanic I Exam-1
Name:
11. The massless, 4-ft-wide gate shown in the figure below pivots about the frictionless hinge O. It is held
in place by the 500 lb counterweight (𝒲𝒲). Determine the water depth, h.
12. Water (assumed frictionless and incompressible) flows steadily from a large tank and exits through a
vertical, constant diameter pipe as shown in the figure. The air in the tank is pressurized to 50 kN/m2.
Determine (a) the height h, to which the water rises, (b) the water velocity at the pipe exit, and (c) the
pressure in the horizontal part of the pipe.