# To All Physics Stoners

Discussion in 'General' started by jimmoman, Jun 4, 2013.

1. I have a question that i cannot seem to find a solid answer, Suppose we have a closed container of any said volume. and we have a lit joint that is producing smoke and what not.

we place the joint/cigarette/hash ball/(anything that produces smoke) inside of the closed container. Now my question is, what happens to the kinetic energy of the smoke? Since there is a limited amount of oxygen the joint/cigarette willl eventually go out in the closed container. But during that time when the joint/cigarette is smoking, what happens to the kinetic energy of the smoke ? it would be easy to say it turns into heat but the actual smoke itself is not changing temperature, only the air or space inside the closed container would change temperature and this would be due to the energy released from the actual lit cherry. But my question is if we only look at the smoke, not the cherry just the physical moving smoke, Where does the kinectic energy of the smoke go? it cannot turn into potential because there is no potential once yu have a closed container with smoke, there is no work that can be done with that so there can;t be any potential energy.

2. from what i think you are asking i'll attempt to answer.
the heat is coming from the burning of the joint and the using up of oxygen. so the joint is no creating energy, the energy is already stored in the joint and the oxygen as potential energy, when it burns that potential energy is turned into kinetic energy. The kinetic energy then disperses throughout the volume of the container. assuming that it is a truly closed system where no energy will escape, the kinetic energy will just disperse evenly throughout the volume of the container and remain there forever.

truly closed systems do no exist in nature though, so what would happen in reality is everything would be the same up until where the kinetic energy disperses evenly throughout the container, and then it would slowly disperse outside of the container until the kinetic energy of the container reached the same level of the kinetic energy inside the container.

3. Yup that about sums it up. The energy would be distributed until it equalized and dispersed evenly throughout the container.

4. Thanks for yur insight , but I'm still a bit confused if the smoke is moving at a initial velocity it won't have the same velocity once it's distributed n equalized it will be moving slower in a more floating type of movement, so for the kinetic energy to stay the same wouldn't the velocity have to stay the same since the mass is not changing ? Greatly appreciate any further knowledge

5. The inertia is spread out into the air since it causes friction which slows down the smoke.

6. so does this mean that in a vacuum the smoke would keep flowing and not equilibrate due to the fact there is no friction

7. #7
Last edited by a moderator: Jun 5, 2013
im aware that gases take on the shape and volume of their container but if the container is an infinitely large resevoir that is a perfect vaccuum (hypothetical) then how can the smoke equilibrate and "lose" some of its kinetic energy

8. Well in space a moving object just keeps going until it hits gravity or another object. The reason the smoke stops in the container is the energy is dispersed through friction as heat which then permeates the container and moves out to the atmosphere.