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.
 

Thread 'Derivation of Hamilton's Principle: Questions'

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...
View full post »

Similar threads

Flow of air through an open tube with a balloon
Replies
9
Views
4K
Air pressure to energy, am I missing something?
Replies
18
Views
2K
How does pressure act in all directions if gravity is downward only
Replies
4
Views
2K
Need help trying to mimic a phenomenon associated with air pressure
Replies
1
Views
2K
Pressure Required to propel something a long distance
Replies
2
Views
2K
Can someone explain the vacuum pressure created by water pressure on waders?
Replies
9
Views
5K
Keeping helium in an unsealed balloon?
Replies
8
Views
2K
Relaxation times of molecules during sound propagation
Replies
3
Views
3K
Exactly how do pressure waves work at the molecular level?
Replies
49
Views
4K
Blowing between two objects -- Why is the pressure low?
2
Replies
76
Views
12K

Hot Threads

Recent Insights

Back
Top