The velocity at which the change from laminar to turbulent flow occurs is:
a) lower than that from turbulent to laminar
b) equal to that from turbulent to laminar
c) higher than that from turbulent to laminar
d) none of these
Answer:
A large cylindrical steel tank 4m. high with its bottom on level ground contains two layers of liquid. The bottom layer is water 2m. deep. The top layer is occupied by a liquid whose specific gravity is not known to a depth of 1m. A 50 mm diam. orifice with a coefficient of velocity of 0.98 is situated one meter from the bottom of the tank. The jet from the orifice hits the ground 2.75m horizontally away from the vena contracta. Determine the sp.gr. of the liquid.
Solution:
Which of the following statements is not in accordance with Pascal’s Law?
a) The pressure is the same in all directions at any point in a fluid at rest.
b) The pressure applied at any point to a liquid in a closed vessel is transmitted undiminished to every portion of the vessel
c) A body submerged in a fluid apparently weighs less by an amount equal to the weighs less by an amount equal to the weight of fluid displaced.
d) None of these
Answer:
Horizontal orifice under a constant head of 1.30m. issues a jet which hits a point 5m. below the centerline of the orifice and 5m horizontally from the vena contrata. What is the coeff. of velocity?
Solution:
What is the discharge capacity of a concrete pipe culvert 4 ft. in diam. And 10m. long if the difference in water level at the outlet is 10m. Assume coefficient of discharge C = 0.74.
Solution:
A watershade covering an area consisting of an equilateral triangle ABC and a square section on the side BC. AV is 1.5km. long. If the storm precipitation depths as measured on the rain gages at A, B and C are 75 mm., 125 mm and 100 mm respectively, compute the average precipitation over the watershed using Thiessen’s polygon method.
Solution:
If the discharge over a 45° triangular weir is 0.021 m3/sec. What is the head if C = 0.594?
Solution:
A vertical jet of water thru a nozzle supports a load of 150 N. The velocity and diameter of the jet at the nozzle tip are 17.46 m/s and 3 cm. Find the distance of load from the nozzle tip in meters.
Solution:
On slow filter, thin gelatinous surface coat of biological growth maybe develop.
a) facultative
b) biomass
c) sludge bulking
d) Shmuthdecke
Answer:
Type of bacteria found in water which lives and developed without oxygen.
a) facultative
b) Bacilli
c) sponge
d) anaerobic
Answer:
Wastewater from a residential community is 400 liters per person per day containing 200 milligram per liter BOD and 240 milligram per liter suspended solids. Determine the number of grams of BOD per person per day.
Solution:
A nozzle situated at ground level issues a jet inclined at 30° with a velocity of 12 m/s. How long will it take before the jet hit the ground?
Solution:
Find the discharge through a rectangular suppressed weir in m3/sec if L = 2.4m. and H = 18cm. Neglect velocity of approach. Use Francis formula.
Solution:
Assuming the same cross sectional area and slope, which of the following channel shapes will give the highest discharge?
Solution:
Wastewater from residential community is 400 liters per person per day containing 240 mg/liter suspended solids. Calculate the number of grams of suspended solids per person per day.
Solution:
A drainage canal in the shape of trapezoid with a bottom width of 2.5m. and sideslope of 1 hor. To 1.5 vertical carries water at a depth of 3m. Find the discharge in m3/sec using Mannings formula. S = 0.0004, n = 0.015.
Solution:
A spillway 12.9m. long releases flood run off from a reservoir 5 hectares in area. If the reservoir level drops from elevation 55m to 54m. in 2520 sec. fond the elevation of the crest of the spillway in meters. Use Francis formula. Assume constant reservoir surface area.
Solution:
A storm drain with a radius of 1.8 m. flows half full. Find the hydraulic radius in meters.
Solution:
If a 5kg steel plate attached to an end of a 0.1 x 0.3 x 1.2m. wooded pole, what is the length of the pole above the water? Use sp.gr. of wood equal to 0.50. Neglect buoyant force on steel.
Solution:
A dam 4m. on top, 10m at the bottom and 20m. high has water 15m. depth acting on its vertical side. What is the factor of safety against sliding if the coefficient of friction is 0.80.
Solution:
Water flows in a rectangular canal having a width of 1m. and a depth of 0.6m. at the rate of 0.07 m3/sec. Determine the type of flow.
Solution:
Compute the critical depth for a rectangular canal having a critical velocity of 4 m/s.
Solution:
With normal barometric pressure at sea level, the atmospheric pressure at an elevation of 1215.5m. in terms of height of mercury is equal to _________. Wt. of air = 11 N/m3 and Hg = 760 mm of air at sea level.
Solution:
A tank contains oil sp.gr. = 0.80, gasoline sp.gr. = 0.9 and sea water sp.gr. = 1.05. What is the pressure at a depth of 1.2m in kg/m2 if the depths of liquids are 0.5, 0.6 and 0.8 m. respectively.
Solution:
A trapezoidal drainage canal has a width of 1.2 m. and 1.8m. at the bottom and top respectively. If n = 0.016, what is the hydraulic radius when flowing 1.2m. deep.
Solution:
A specimen of moist clay has a mass of 183.4 grams. After oven drying, the mass is reduced to 157.7 grams. Compute the moisture content of the sample.
Solution:
Determine the discharge through a trapezoidal weir whose sides are at an angle of 14°01’11” from the vertical and the crest length is 1.5m. long. The head on the weir is 0.3m.
Solution:
A tank contains three liquids. Oil with sp.gr. of 0.8, gasoline with sp.gr. of 0.90 and see water with a sp.gr. of 1.05 with depths of 0.65, 0.45 and 0.55 m. respectively. Compute for the water pressure at a depth of 0.80 m.
Solution:
A fluid flows through a 1000m. long and 12 mm. diam. glass tube. In 2 minutes 0.015 m3. of fluid passes through the tube. If head loss is 0.20 meter, what is the Reynolds Number. Assume laminar flow.
Solution:
The discharge in a rectangular flume of most efficient section(b = 2d) is 9 cu.m/sec. If the velocity of flow is 1.2 m/s, find the slope required for uniform steady flow. Use Chezy’s c = 50 (S.I. units)
Solution:
A suppressed rectangular weir is under a head of 32m. The width of the channel upstream of the weir is 2.5m. and water stands 1.25m. deep. Using the Francis formula, find the discharge in m3/sec. Neglect velocity of approach.
Solution:
A dam 40m. high has a spillway discharging at 2m. deep and a crest length of 10m. If c = 3.2, find the discharge in cu.m. sec.
Solution:
A masonry dam 6m. on top, 18m. at the bottom and 24m. high has water 20m. deep on its vertical side. What is the factor of safety against sliding? Assume weight of masonry as 2400 kg/m3. and coefficient of friction is 0.80.
Solution:
A 600 mm. diameter water main is bent at an angle of 45° from the horizontal. What vertical component of dynamic pressure is developed in the bend if the velocity in the pipe is 2 m/s?
Solution:
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