PHEP 2 Flashcards
Potential energy is most nearly associated with?
Force
The accomplishment of a force acting through a distance is associated with?
Work
Energy available for future use is called?
Potential
The term “power” means?
Rate at which work is done
Falling water contains…
Kinetic energy
The acceleration of a freely falling body due to the force of gravity is?
32 ft per second (32 ft/sec^2)
A foot-pound is a unit of?
Work
In five seconds of fall, a falling body will fall a total of how many feet?
400 distance= 1/2(g t^2)
The theoretical velocity of a freely falling body is equal to?
Sq root (2gh)
If the velocity of a stream of water is doubled, the weight of a material it can suspend and carry is increased by?
16
A pump raises 200 cubic feet of water to a height of 50 feet. How much work was done to raise this water?
624,000 ft-lbs
If the water in “A pump raises 200 cubic feet of water to a height of 50 feet. How much work was done to raise this water?” question is raised in five minutes, at what rate in horsepower is the work done?
3- 3/4
Niagara Fails is 180 feet high. At the top of the fails each cubic foot of water (weight 62 4 ibs) has how many foot -pounds of potential energy?
9984
The transfer of the kinetic energy contained in falling water to mechanical energy at the blades of a hydraulic turbine involves the application of what law?
all three laws
Increasing the velocity of falling water will?
Increase the available kinetic energy
Disregarding all other losses rate of flow of a liquid is the product of?
Area x velocity
If the diameter of a pipe is decreased uniformly at its termination and with no change in pressure head, the exit velocity of the liquid…
Is increased
With continuous steady flow, the total head at any point in a stream is equal to the total head at any downstream point plus the…?
loss of head between the two points
The sudden transformation within a pipe of the kinetic energy of the moving mass of water into pressure energy is most usually associated with?
water hammer
The damaging effects of water hammer can be controlled by?
effective application of all three of the above
Compute the approximate friction loss in feet of head for a section of pipe having a diameter of 2 feet, 1000 feet long, roughness coefficient of 0.02 and a mean velocity of 10 ft/sec
15
Compute the approximate loss of head in feet due to turbulence for the above pipe, assuming a square edge entry.
3/4
The head causing flow through a pipe is the difference between the total head at the beginning of the pipe and the…
total head at the end of the pipe
Two reservoirs have surface elevations of 200 and 100 ft. Calculate the approx. flow rate in gals/min through the interconnecting pipe. Assume a square edge entry, clean steel pipe, diameter 1- 1/2 ft, length 600 ft and a coefficient “f” of 0.02.
Between 20,000 and 21,000
When applied to a moving liquid mass, the expression (y^2)/2g refers to
velocity head
