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WorksheetsPTT156 Energy and Energy Balances
Total questions: 10
Worksheet time: 7mins
What forms of energy may a system possesses?
Kinetic and Potential
Heat and Work
Internal energy
All of above
In what forms may energy be transferred?
Kinetic Energy
Potential Energy
Internal Energy
Heat
Work
Why is it meaningless to speak of the heat possessed by a system?
Heat can be transferred via conduction, convection and radiation.
Heat is a form of energy transfer from a region of high temperature to another region of lower temperature.
Heat is only defined in terms of energy being transferred.
What do the terms closed system and open system mean?
Closed system: No mass crosses system boundaries.
Closed system: No energy crosses system boundaries.
Open system: Mass crosses system boundaries.
Open system: Energy crosses system boundaries.
What is an adiabatic process?
No moving part or generated currents.
The system is stationary.
No heat transferred to or from system.
No vertical displacement.
Under what circumstances might U be considered independent of pressure for a pure substance?
No temperature changes.
Under nearly ideal conditions.
No phase changes.
No chemical reactions occur.
How would you simplify the open-system energy balance equation, when:
There is no moving parts in the system.
Ẇ = 0
Ẇfl = 0
Ẇs = 0
How would you simplify the open-system energy balance equation, when:
The system and its surroundings are at the same temperature.
Ẇs = 0
Q̇ = 0
∆Ėp = 0
∆Ėk = 0
How would you simplify the open-system energy balance equation, when:
The linear velocities of all streams are the same.
∆Ėp = 0
Ẇs = 0
∆Ėk = 0
Q̇ = 0
How would you simplify the open-system energy balance equation, when:
All streams enter and leave the process at a single height.
Q̇ = 0
Ẇs = 0
∆Ėk = 0
∆Ėp = 0
