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

#### Ashley1nOnly

1. The problem statement, all variables and given/known data

2. Relevant equations

3. 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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#### Baluncore

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.

#### Ashley1nOnly

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.

#### Baluncore

Where does the question come from ?

#### Baluncore

Then you need to contact your professor and get a clarification on the question.

#### Ashley1nOnly

So there's a piston with a crank attached that is connected to a container.

#### Nidum

Gold Member
(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 .

#### Delta2

Homework Helper
Gold Member
(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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"Piston with crankshaft: what is the temperature of gas entering the cylinder?"

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