Piston with crankshaft: what is the temperature of gas entering the cylinder?

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Homework Help Overview

The discussion revolves around a problem involving a piston and crankshaft system, specifically focusing on the temperature of gas entering a cylinder. Participants are trying to understand the setup and the implications of energy transfer within the system.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants are questioning the clarity of the problem statement and the absence of a diagram. There are discussions about the mechanics of the piston and crank, the source of the gas, and the thermodynamic implications of energy transfer and pressure changes.

Discussion Status

The conversation is ongoing, with participants expressing confusion about the problem's details and seeking clarification. Some suggest that the question may be poorly formulated or a variation of a known problem. There is no explicit consensus on the interpretation of the question, but various lines of reasoning are being explored.

Contextual Notes

Participants note the lack of a diagram and the potential for miscommunication regarding the problem's requirements. There is mention of assumptions about the system being thermally isolated and the nature of the energy transfer involved.

Ashley1nOnly
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Homework Statement


upload_2017-12-16_0-30-53.png


Homework Equations

The Attempt at a Solution


e) I know the temperature is lower in the transparent container but how do you represent this
 

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We seem to be missing a diagram.
A piston is pinned but then a crank is turned? Is there a separate piston pump?
Where does the gas come from that goes to the transparent container?

If it takes energy to transfer the gas, then the gas pressure must rise, which suggests it suddenly increases in pressure and so temperature. Then it slowly cools by radiation back to the transparent containers external ambient temperature, pressure falls during the process.
 
I wasn't given a diagram. I was hoping that maybe someone could tell me what the problem wanted.
I'm thinking the piston is attached to the crank and that there is gas already in the system.
 
Where does the question come from ?
 
My professor made it up
 
Ashley1nOnly said:
My professor made it up
Then you need to contact your professor and get a clarification on the question.
 
So there's a piston with a crank attached that is connected to a container.
 
(1) Either this question has lost clarity and detail in transcription or your professor has very little understanding of physics .

(2) This might be a garbled version of a similar question that I have come across before . In that there was a screw being driven by the crank and the action of the screw propelled the piston down through a cylinder . N turns of the screw with a known applied torque gave a value for work done .​
 
Nidum said:
(2) This might be a garbled version of a similar question that I have come across before . In that there was a screw being driven by the crank and the action of the screw propelled the piston down through a cylinder . N turns of the screw with a known applied torque gave a value for work done .​
I think that's what the question is trying to tell us , that is that the work done to the gas is ##n2\pi l F## and since the chamber is thermally isolated and we assume the transfer to be instantaneous ##\Delta U+W=0## and from this to calculate the ##\Delta T## to answer perhaps e). But yes since it says the piston is fixed, don't know what crank is that that does work to the system. Also instantaneous transfer that takes n turns of a crank doesn't seem too orthological either...
 
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