Fluid Mechanics — Quiz 3

Questions in this quiz (10)

1. Question — A $$4\ \text{m}$$ deep tank is filled with oil of relative density $$0.85$$. The atmospheric pressure at the surface is $$101\ \text{kPa}$$. The absolute pressure $$\left(\text{kPa}\right)$$ at the bottom of the tank is most nearly:

   • 118
   • 134
   • 145
   • 165

2. Question — A $$12\ \text{ft}$$ deep tank contains $$7\ \text{ft}$$ of water and $$5\ \text{ft}$$ of oil with relative density of $$0.80$$. The pressure $$\left(\text{psf}\right)$$ at the bottom of the tank is most nearly:

   • 420
   • 610
   • 725
   • 910

3. Question — A dam is $$120\ \text{ft}$$ long. It is $$15\ \text{ft}$$ high from its base with $$13\ \text{ft}$$ of water behind it. The sliding force caused by hydrostatic pressure $$\left(\text{kips}\right)$$ is most nearly:

   • 95
   • 110
   • 520
   • 610

4. Question — For the dam cross-section shown, the maximum overturning moment $$\left(\text{ft-k}\right)$$ over its $$120\ \text{ft}$$ length is most nearly:

   • 650
   • 1,950
   • 2,350
   • 3,100

5. Question — A $$4\text{-in}$$ wide (horizontal direction) and $$4\text{-ft}$$ long (vertical direction) strip is removed from a steel tank wall that contains water under a head of $$12\ \text{ft}$$. A steel plate is installed and welded all around. The force $$\left(\text{lb}\right)$$ on the weld is most nearly:

   • 720
   • 865
   • 1040
   • 1280

6. Question — The steady incompressible flow in pipes is expressed by Bernoulli's equation: Which of the following statements about minor losses is correct?

   • They are determined using Reynolds number only
   • They represent losses at fittings and valves
   • They apply only to laminar flow
   • They are independent of velocity

7. Two pressure gages are attached on the side of a tank filled with a liquid. The first gage is located $$4\ \text{m}$$ from the bottom of the tank and reads $$92\ \text{kPa}$$. The second gage is located $$9\ \text{m}$$ from the bottom and reads $$48\ \text{kPa}$$. The density of the liquid $$\left(\text{kg/m}^3\right)$$ is most nearly:

   • 410
   • 865
   • 1120
   • 720

8. In model similarity, if viscous and inertial forces are the only important forces, which number is kept constant in similitude?

   • Froude number
   • Reynolds number
   • Weber number
   • Mach number

9. A nozzle of $$3\text{-in}$$ diameter delivers a stream of water at a velocity of $$150\ \text{ft/s}$$ perpendicular to a rigid plate. The force $$\left(\text{k}\right)$$ required to hold the plate is most nearly:

   • 12
   • 28
   • 4
   • 85

10. Two plates are kept $$5\ \text{mm}$$ apart and the space between them is filled with oil of dynamic viscosity $$0.15\ \text{Pa}\cdot\text{s}$$. The lower plate is fixed and the upper plate is movable. If the upper plate is moved with a velocity of $$1.5\ \text{m/s}$$, the shear stress $$\left(\text{Pa}\right)$$ on the lower plate is most nearly:

    • 45
    • 60
    • 75
    • 90