Is F in P=F/A an average or a sum of all microscopic forces?

AI Thread Summary
The force F in the pressure formula P=F/A is indeed considered an average of the microscopic forces exerted by gas particles on the container walls over time. This average accounts for the random fluctuations in collisions from numerous particles. While it may seem like a sum of forces from individual particles, the averaging process is essential for obtaining a stable pressure measurement. The discussion emphasizes the importance of time in this averaging to accurately reflect the behavior of gas particles. Understanding this concept is crucial for grasping gas behavior in physics.
Greg777
Messages
11
Reaction score
0
Hello,
I've read that the force F we use in the pressure formula P=F/A is an average of all microscopic forces exerted by the gas on the wall of the container over a period of time. Is it true? I thought it was a SUM rather than an average?
I assume that in that definition the microscopic force is a force exerted by a SINGLE particle on the wall.
 
Physics news on Phys.org
It's a sum over all the different particles, but an average over time. When the text talks about averaging, it should be talking about averaging over time to smooth out the random fluctuations of collisions with particles.
 
  • Like
Likes Greg777

Thread 'Off resonant driving of a MW/RF cavity'

Hello! Let's say I have a cavity resonant at 10 GHz with a Q factor of 1000. Given the Lorentzian shape of the cavity, I can also drive the cavity at, say 100 MHz. Of course the response will be very very weak, but non-zero given that the Loretzian shape never really reaches zero. I am trying to understand how are the magnetic and electric field distributions of the field at 100 MHz relative to the ones at 10 GHz? In particular, if inside the cavity I have some structure, such as 2 plates...
View full post »

Similar threads

I Wall material effect on Van der Waals gas?
Replies
23
Views
2K
B Determine forces acting on double inclined plane
Replies
13
Views
2K
I Mechanical power generated by a force F
Replies
41
Views
4K
I Work in hydrostatic system in cylinder with piston: P_int or P_ext?
Replies
5
Views
2K
I Summing and averaging RMS pressure (amplitude) of sound waves
Replies
2
Views
2K
I How come there is a buoyant force?
Replies
12
Views
2K
I Why pressure stays the same when doubling both volume and temperature?
Replies
35
Views
4K
Average power used to stretch a spring
Replies
10
Views
2K
Does radiation pressure depend on the wave phase?
Replies
9
Views
2K
I What are the effects of Buoyancy & G-force combined in this scenario?
Replies
9
Views
2K

Hot Threads

Recent Insights

Back
Top