Calculating Delta P in Vacuum Chambers: P1 or 0?

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Discussion Overview

The discussion revolves around the calculation of delta pressure (ΔP) in vacuum chambers, specifically whether to substitute P1 with zero when considering scenarios without air. The context includes theoretical considerations and practical implications related to pressure differences in vacuum environments.

Discussion Character

  • Debate/contested

Main Points Raised

  • One participant questions whether P1 should be substituted with zero in the calculation of ΔP in vacuum chambers, suggesting that without air, the equation may not apply.
  • Another participant seeks clarification on the initial query, indicating a need for more context regarding the discussion.
  • A participant proposes that in a vacuum chamber scenario, such as shaking a cola can, the driving force upon opening would be zero due to a lack of ΔP, implying that without air, ΔP cannot exist.
  • In response, another participant challenges the assertion that there is no ΔP, arguing that a cola bottle contains high pressure internally while the external pressure is near zero, suggesting that a pressure difference does exist.

Areas of Agreement / Disagreement

Participants express differing views on whether ΔP can be considered zero in the absence of air, indicating that the discussion remains unresolved with multiple competing perspectives.

Contextual Notes

There are assumptions regarding the definitions of pressure in vacuum conditions and the implications of high internal pressure versus low external pressure that remain unaddressed.

ahmed11
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in calculating the delta p in vacuum chambers do we substitute p1 with 0 or the whole equation doesn't exist if air doesn't exist?
 
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Could you elaborate on what it is that you are exactly talking about?
 
CrazyNinja said:
Could you elaborate on what it is that you are exactly talking about?
i mean if we shook a cola can in vacuum chamber then the driving force when opened will be zero because there is no delta p. right?
without air then there won't be delta p.
or we assume that p 1 is equal to p2 is equal to zero?
do you get what i mean
 
Why do you think there is no ΔP? (In case you are wondering, there is a "symbols" section in the text from where you can get a "Δ" ). The cola bottle is packed with high pressure and the pressure outside is close to zero.
 

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