- #1
nilesthebrave
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Homework Statement
1, 2, and 3 use the following information: a cylinder is closed at both ends and has adiabatic walls. It is divided into two compartments by a movable, frictionless, adiabatic piston. Initially the pressure, volume, and temperature on both sides are equal and given by P=10.0 atm, V=100 Liters and T=300k. The gas is perfect(ideal) with the MOLAR heat capacity of Cv=3R/2(Joules/mol.K)). By means of a heating coil, which is switched on at time t=0, heat is supplied to the compartment on the left, causing the piston to move and the pressures and volumes of the gas in the two compartments to change. A constant current of 10.0 Amps flows through the heating coil; the potential difference across the coil is 100.0 Volts. Assume the power of the heater is also at which heat is delivered to the gas on the left. The heater is turned on for 303.0 seconds, and the system is allowed to come to a new equilibrium. For this new equilibrium state, calculate:
1.The pressure in atmospheres of the gas in the right hand compartment.
2. The volume of the right hand compartment.
3. The final temperature of the left hand compartment
Homework Equations
PV=nRT
dW=PdV
du=dq+dW
P1V1=P2V2
Power=I*Voltage
Power=work/time
The Attempt at a Solution
I've found the work to be 303 kJ. I also know that the final pressure on both sides will equal each other. I know that the piston will expand to the right, increasing the volume of the left, while decreasing the volume on the right. I know that because this is an adiabatic closed system that the change in internal energy will be zero.
I'm fairly sure that the temperature will go up on the right hand side but I'm not 100% sure.
I worked out a very roundabout way of solving this problem, which involved doing the questions out of order. My professor assured me there is an easier and more efficient way of solving this problem by doing them in order, which is why he presented it in this order.
My problem is that since I don't know any of the final conditions, how can I determine what any of them are in this order? For instance I know I could integrate PdV=dW, but I need the final volume to have my bounds of integration.
So I know I'm missing something simple here. Can I do something with the fact that the total volume of this cylinder is 200L? Or is there a way to determine pressure using the work and time? I've searched high and low for some way to do this and I really have no idea.