Different kinds of Kinetic energy

Click For Summary
Translational kinetic energy refers to the energy associated with the movement of molecules from one location to another, while rotational kinetic energy pertains to the rotational motion of those molecules. The discussion highlights confusion regarding the relationship between average kinetic energy, internal energy, and their equations, particularly the expression \(\frac{3}{2}k_{b}T\), which relates to the average kinetic energy per molecule in a gas. Clarification is sought on terms like moles, molecules, and molar mass, with an emphasis on understanding their meanings beyond equations. The participant also questions the interchangeability of kinetic energy, internal energy, and work, noting their conceptual differences despite having the same units. Understanding these concepts is essential for grasping thermodynamics and molecular motion.
AznBoi
Messages
470
Reaction score
0
I'm studying thermodynamics and I've come across different types of KE's in the motion of molecules within gases. What is "translational kinetic energy?" Is "rotational kinetic energy" just the rotational movement of the molecules?
 
Physics news on Phys.org
"Kinetic energy is the energy of motion. An object which has motion - whether it be vertical or horizontal motion - has kinetic energy. There are many forms of kinetic energy - vibrational (the energy due to vibrational motion), rotational (the energy due to rotational motion), and translational (the energy due to motion from one location to another)."

You can find that information anywhere on the internet. Just search Google.
 
husky88 said:
"Kinetic energy is the energy of motion. An object which has motion - whether it be vertical or horizontal motion - has kinetic energy. There are many forms of kinetic energy - vibrational (the energy due to vibrational motion), rotational (the energy due to rotational motion), and translational (the energy due to motion from one location to another)."

You can find that information anywhere on the internet. Just search Google.

oh okay. I just didn't know what the word "translational" meant. Also, are the internal energy and avg KE both equal to: \frac{3}{2}k_{b}T?? Is this true because the internal energy is basically all of the KE and PE's of molecules within the system? I'm referring to the avg KE and internal energy per molecule and not the total KE and internal energy
 
I'm kind of getting confused on moles, molecules, molar mass, mass of the molecules. Does anyone mind making these terms more clearer to me? I can only figure their meanings through equations and even if I do I still don't know their real meanings.

n=\frac{N}{N_{A}} \qquad m*N_{A}=M

I especially don't get the molar mass equation, here is what I did to somewhat get a sense of the meanings:

[\frac{mass}{#molecules}*\frac{#molecules}{mole}=\frac{mass}{mole}]

m is the mass of all of the molecules correct? Which would also be equal to the total weight of the gas??
 
I'm reading my text and it seems like KE=\Delta U=W can these three variables be used interchangably but not conceptually? I keep getting mixed up with these three and would like to know if they are always equal to each other. I know that U relates to the microscopic molecular energies of the system so their units are all the same but..
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

Similar threads

  • · Replies 21 ·
Replies
21
Views
5K
  • · Replies 10 ·
Replies
10
Views
801
  • · Replies 7 ·
Replies
7
Views
1K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 9 ·
Replies
9
Views
2K
Replies
3
Views
1K
  • · Replies 33 ·
2
Replies
33
Views
3K
Replies
9
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K
Replies
2
Views
1K