The elastic collisions of gas

[Forestman]

I have read that when a gas atom or molecule collides with the wall of a container that the collision is completely elastic, and that the gas particle has the same energy after the collision as it did before the collision. I don't understand how it could transfer pressure to the container wall if it did not lose energy though.

 

[dE_logics]

Pressure being transferred doesn't mean work is being done.

For work to be done there should be a pressure along with a volume change.

 

[astrokreng]

Elastic collisions in gases are a fundamental concept in the study of thermodynamics and fluid mechanics. The idea that gas particles maintain their energy after colliding with the walls of a container is a fundamental principle in understanding the behavior of gases.

To understand this concept, we must first understand the concept of pressure in gases. Pressure is the force exerted by gas particles on the walls of a container. In an elastic collision, the gas particle does not lose energy, but it does change direction. This change in direction results in a transfer of momentum to the container wall, creating a force and thus, pressure.

Think of it like a game of billiards. When a billiard ball collides with another ball, it transfers its momentum to the other ball, causing it to move. Similarly, when a gas particle collides with the wall of a container, it transfers its momentum to the wall, causing it to exert a force and thus, pressure.

In an ideal gas, where the particles are considered to be point masses with no intermolecular forces, the collisions are perfectly elastic. This means that the total kinetic energy of the gas particles remains constant, and no energy is lost during collisions.

In real gases, there may be some energy loss due to intermolecular forces or non-ideal behavior, but the overall concept of elastic collisions still applies. The gas particles still transfer momentum to the container walls, creating pressure.

In conclusion, the concept of elastic collisions in gases is crucial in understanding the behavior of gases and the transfer of pressure to container walls. While it may seem counterintuitive that a particle can transfer momentum without losing energy, it is a fundamental principle that has been observed and studied extensively in the field of thermodynamics.