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Why we do not considered the translational energy of the gases particles in the internal energy due to ordered motion but only due to random motion.
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Because we can always find an inertial frame in which the translational energy is zero; it's the center of mass frame. The internal energy is whatever cannot be transformed away just by changing frames, the energy that is there even when the center of mass is not moving.Hemant said:Why we do not considered the translational energy of the gases particles in the internal energy due to ordered motion but only due to random motion.
In the general form of the first law of thermodynamics, the energy of the gas is expressed as the sum of three parts: the kinetic energy of the ordered motion KE plus the gravitational potential energy PE, plus the combined energy of random motion and molecular interaction (the internal energy U). So we write:Hemant said:Why we do not considered the translational energy of the gases particles in the internal energy due to ordered motion but only due to random motion.
Nugatory said:The internal energy is whatever cannot be transformed away just by changing frames, the energy that is there even when the center of mass is not moving.
Yes, but in thread we're talking about kinetic energy.DrStupid said:Wouldn't that include potential energy in an external field (which is not part of internal energy)?
Nugatory said:Yes, but in thread we're talking about kinetic energy.
Sure, in non-relativistic physics it's usually customary to express everything in "quantities per mass", i.e., the energy density of an ideal fluid with velocity ##\vec{v}## may be written asDrStupid said:Wouldn't that include potential energy in an external field (which is not part of internal energy)?
Hemant said:Can anyone please give the reason of the line written in the box.
Thanks,Nugatory said:Because we can always find an inertial frame in which the translational energy is zero; it's the center of mass frame. The internal energy is whatever cannot be transformed away just by changing frames, the energy that is there even when the center of mass is not moving.
Hemant said:Can anyone please give the reason of the line written in the box.
I was just seeing my old posts that I didn't understand quite well and after seeing your this answer I was just blown away because earlier in that time I was just thinking that it's answer will be out of the world but its answer is so simple that now I think that how one can even ask question like that.Vanadium 50 said:Um, B-level, everyone.
Why do we do not consider ordered motion as part of the internal energy of a gas?
Because wind and heat are different things.
Ordered motion, also known as macroscopic motion, refers to the overall movement of a gas as a whole. This type of motion does not contribute to the internal energy of a gas because it does not involve the random movement of individual particles within the gas. The internal energy of a gas is determined by the kinetic energy of the particles and their interactions, not the overall motion of the gas.
The internal energy of a gas is directly related to its temperature. As the temperature of a gas increases, the average kinetic energy of its particles also increases, resulting in a higher internal energy. This is because the particles are moving faster and colliding more frequently, leading to a greater amount of energy in the system.
No, ordered motion does not contribute to the pressure of a gas. Pressure is determined by the force of the gas particles colliding with the walls of their container. Ordered motion does not involve these collisions and therefore does not impact the pressure of the gas.
During a phase transition, such as from a liquid to a gas, the internal energy of a gas remains constant. This is because the energy is used to overcome the attractive forces between the particles and break the bonds holding them together, rather than increasing the kinetic energy of the particles.
Yes, the internal energy of a gas can be affected by external factors such as changes in temperature, pressure, and volume. These changes can alter the kinetic energy and interactions of the particles within the gas, resulting in a change in the internal energy of the system.