What is the difference between pressure and energy?

  • Thread starter Thread starter Hypo
  • Start date Start date
  • Tags Tags
    Energy Pressure
AI Thread Summary
Pressure is defined as force per unit area applied perpendicular to a surface, while energy is the capacity to perform work. In the context of a compressed gas, such as from a tank or balloon, the gas molecules in motion possess kinetic energy and exert force as they escape. The pressure created by compression allows the gas to do work on the surrounding environment as it exits. Although pressure and energy are related, they are distinct concepts; for example, two balloons at the same pressure can have different energy levels based on their size. Understanding these differences is crucial for grasping the principles of fluid dynamics and energy transfer.
Hypo
Messages
58
Reaction score
0
Hallo everyone!

Im new here on this forum and I had a few questions in mind I would like to share them with everyone to get a perfect understanding with what I'm dealing with.

Now what is Pressure exactly? Is it a force or energy? I am kinda confused about it...?

For example the pressure from a compressed air tank blowing out through a small spot is that energy or force coming out?

Another example a balloon having a very very small poked whole to it... The air coming out from the pressure is that energy or force?

Thank you everyone :)
 
Physics news on Phys.org
Energy is the ability for one system to perform work on another system. A compressed gas or a balloon has the ability to perform work on the gas outside by releasing it's own compressed gas. The gas has lots of kinetic energy as it exits the tank/balloon thanks to pressure generated by the compression inside the tank, or the squeezing by the balloon. So to answer your question, it is neither energy nor force coming out of the tank or balloon, it is gas molecules that are in motion which have energy and exert a force on other molecules.

The definition of pressure itself is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure.
 
Consider a second balloon, twice the size of the first, same pressure. It has twice the potential to do work (energy), but the same pressure, so they're different things.

Consider a vessel of compressed gas with a bung in the top. A wide bung would be hard to keep in because its area is larger. Force = pressure times area.
 
This has been discussed many times on PF, and will likely come up again, so the video might come handy. Previous threads: https://www.physicsforums.com/threads/is-a-treadmill-incline-just-a-marketing-gimmick.937725/ https://www.physicsforums.com/threads/work-done-running-on-an-inclined-treadmill.927825/ https://www.physicsforums.com/threads/how-do-we-calculate-the-energy-we-used-to-do-something.1052162/
Thread 'Is 'Velocity of Transport' a Recognized Term in English Mechanics Literature?'
Here are two fragments from Banach's monograph in Mechanics I have never seen the term <<velocity of transport>> in English texts. Actually I have never seen this term being named somehow in English. This term has a name in Russian books. I looked through the original Banach's text in Polish and there is a Polish name for this term. It is a little bit surprising that the Polish name differs from the Russian one and also differs from this English translation. My question is: Is there...
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...
Back
Top