Pressure at different altitudes

  • Thread starter Thread starter Sp4rk
  • Start date Start date
  • Tags Tags
    Pressure
AI Thread Summary
The pressure in an airtight container does change with altitude due to temperature variations. When a sealed bottle of air is taken to higher altitudes, the external pressure decreases, but the internal pressure remains constant if volume and particle number are unchanged. The ideal gas law (PV=NkT) indicates that pressure is dependent on temperature; thus, if temperature changes, internal pressure may also change. While the internal pressure can remain stable if temperature is constant, the pressure differential between the inside and outside of the bottle will vary significantly with altitude. Understanding these principles is essential for predicting pressure behavior in sealed containers at different altitudes.
Sp4rk
Messages
1
Reaction score
0
Hi, I was wondering if the pressure in an airtight container changes with different altitudes?

For example, I seal an empty bottle of water (just air in it) at sea level so no air can leave or enter it. I then send the bottle to an altitude of 100km above Earth, will the pressure change in it? How come if it does and what equations are used?

Thanks!
 
Physics news on Phys.org
The pressure inside the bottle will probably chance since at higher altitudes the temperature changes.

For an ideal gas (for which air is a pretty good fit) we have PV=NkT where P is the pressure, V is the volume, N is the number of particles contained in the volume, k is the Boltzmann constant, and T is the temperature.

So one see that P will not change if V,N, and T remain fixed. In this case, V and N can remain fixed, but T probably changes between the altitudes. If you kept the container at a constant temperature, then probably the pressure wouldn't change inside the bottle.

The pressure outside the bottle definitely changes (it is simply the pressure of the ambient air) and therefore the total pressure differential between the inside and outside of the bottle changes.
 
Hi there, im studying nanoscience at the university in Basel. Today I looked at the topic of intertial and non-inertial reference frames and the existence of fictitious forces. I understand that you call forces real in physics if they appear in interplay. Meaning that a force is real when there is the "actio" partner to the "reactio" partner. If this condition is not satisfied the force is not real. I also understand that if you specifically look at non-inertial reference frames you can...
I have recently been really interested in the derivation of Hamiltons Principle. On my research I found that with the term ##m \cdot \frac{d}{dt} (\frac{dr}{dt} \cdot \delta r) = 0## (1) one may derivate ##\delta \int (T - V) dt = 0## (2). The derivation itself I understood quiet good, but what I don't understand is where the equation (1) came from, because in my research it was just given and not derived from anywhere. Does anybody know where (1) comes from or why from it the...
Back
Top