Exam 1 part 2 Flashcards
A normal (perpendicular) force distributed over an area is known as:
pressure
When the pressure less than atmospheric pressure, this is known as a Answer
vacuum
The resultant pressure force acting on an area is located at a point known as the
center of pressure
The moment of inertia is needed to find the location of the resultant force on a surface. This can be determined using integration, or more simply, by using the
Parallel axis theorem
A 100’ tall by 500’ wide vertical rectangular dam is holding creating a reservoir of water. The depth of water at the dam is 60’. If the specific weight of water is 62.4 lb/ft^3, the hydrostatic force acting on the dam is most nearly:
=56200 kip
= 62.4 * 60 feet *(30’ * 500 ft)
Streamlines are lines defined where the velocity vectors of a fluid field are ____________
to the line at every point and time
Tangent
When the velocity of a fluid does not change from one point to another point along the path of the streamline, this is classified as
Uniform Flow
When the magnitude and direction of the fluid does not change over time, this is classified as
Steady flow
The index used to assess whether floc can be classified as laminar or turbulent is called the
Reynolds number
The continuity equation is based on the control volume approach to represent the
conservation of mass
The total energy in a hydraulic system the sum of which 3 types of energy?
internal energy, kinetic energy, potential energy
The energy equation is based on which law of thermodynamics?
1st
The work done by a hydraulic system can be classified into two types of work. Name these.
shaft work, flow work
In one or two sentences, and in your own words, explain the need for a kinetic energy correction factor (alpha)
Since the V used represents the average velocity but is not the true velocity. Alpha estimate the difference between the actual velocity distribution and the idealized uniform profile
