Work to pump out air from cylinder

AI Thread Summary
To calculate the work needed to pump air from a cylinder, the formula W = pV can be used, where V is the volume of the cylinder calculated as V = Sl (length times cross-sectional area). The initial pressure is not specified in the problem, leading to the consideration of using atmospheric pressure as a reference. This approach is valid as long as the pressure conditions are understood. The discussion emphasizes the importance of defining pressure when solving for work in this context.
Stefan

Homework Statement


[/B]
I know only the length (l) and cross-section area (S) of an air tank, cylinder. The question is how much work is needed to pump out air from the cylinder.

Homework Equations

The Attempt at a Solution


Is it correct to use here the formula
W = pV?
The initial pressure isn't defined in the content of the task, so I am also wondering if I can use as it the atmospheric pressure.
 
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What do you mean by cylinder ?

An air tank or the working cylinder of an air pump ?
 
Air tank.
 
Stefan said:

Homework Statement


I know only the length (l) and cross-section area (S) of an air tank, cylinder. The question is how much work is needed to pump out air from the cylinder.

Homework Equations


3. The Attempt at a Solution [/B]
Is it correct to use here the formula
W = pV?
The initial pressure isn't defined in the content of the task, so I am also wondering if I can use as it the atmospheric pressure.
There may be more than one answer to this question, but the method I have in mind would definitely agree with your answer: Work = pV, V = Sl, p = 1 at.
 
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