(a)
Draw the PV diagram of the closed cycle.
(a)
Answer to Problem 34P
The PV diagram for the closed cycle is drawn.
Explanation of Solution
An adiabatic process occurs without transfer of heat or mass of substance between a
An Isobaric process is a thermodynamic process in which the pressure stays constant. The heat transferred to the system does work, but also changes the internal energy of the system.
Conclusion:
The figure 1 shows the PV diagram for the ideal gas expands adiabatically to its original pressure and compressed isobarically to its original volume.
(b)
The volume of the gas at the end of the adiabatic expansion.
(b)
Answer to Problem 34P
The volume of the gas at the end of the adiabatic expansion is
Explanation of Solution
Write the expression from PV diagram at the point B and C.
Here,
Conclusion:
Rewrite the above expression from the PV diagram to find volume.
Here,
Therefore, the volume of the gas at the end of the adiabatic expansion is
(c)
The temperature of the gas in an adiabatic expansion.
(c)
Answer to Problem 34P
The temperature of the gas in an adiabatic expansion is
Explanation of Solution
Write the expression from ideal
Here,
Write the expression from the PV diagram
Here,
Conclusion:
Compare equation (II) and (III) to find
Therefore, the temperature of the gas in an adiabatic expansion is
(d)
The temperature at the end of the cycle.
(d)
Answer to Problem 34P
The temperature at the end of the cycle is
Explanation of Solution
Write the expression for temperature for whole cycle.
Here,
Conclusion:
Therefore, the temperature at the end of the cycle is
(e)
The net work done on the gas.
(e)
Answer to Problem 34P
The net work done on the gas is
Explanation of Solution
Write the expression for energy transfer between the points AB.
Here,
Replace
Write the expression for energy transfer for adiabatic process between the points BC.
Write the expression from ideal gas law.
Here,
Replace
Write the expression for energy transfer between the points CA.
Here,
Replace
Conclusion:
Find the energy transfer for whole cycle.
Substitute the equation (V), (VI) and (VII) in above equation.
Rewrite the above equation.
Find the internal energy for whole cycle.
Here,
Substitute equation (VIII) in the above equation.
Therefore, the net work done on the gas is
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Chapter 21 Solutions
Physics for Scientists and Engineers With Modern Physics
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