hi, im new to this physics stuff and trying to get a better idea of things etc... When molecules moves (large or small doent matter) it creates Kinetic energy, therefore also increasing heat in and around the molecules (group of molecules). If it was to stop and not be 'destroyed\transfomed', is it right to assume that the molecules would therefore be at a higher temperature than when they were before hand? (in accordance to the sarroundings such as heat temperature of the air etc...) I understand how energy is 'translated' into heat and vice versa but can someone please explain to me as to why we see the 'energy' of the molecules as 'heat', or is it just a way for us to describe the 'heat' and how it is 'created'? If heat is energy, could we say that induction is infact simplly changing the energy levels trying to reach a state of eqealibrium which is more or less balancing the energy levels and 'heat' is a way of 'seeing' this? If 'stating' heat is a way of measuring the amount of energy in certain molecules, is it just basically energy that affects differant molecules in differant ways (such as temperature, liquid to gas)? Like i said iv only recentally started studying physics, just a few weeks and sometimes speak 'yoda'. really enjoy it and starting my degree very soon, hopefully Please Register or Log in to view the hidden image! Please Register or Log in to view the hidden image! Please Register or Log in to view the hidden image!
If it moves then it has kinetic energy but that doesn't mean it 'created it'. That energy must have been input from somewhere else. For instance, if you drop a brick the gravitational potential energy the brick has by virtue of its position in the Earth's gravitational field is converted into kinetic energy. Temperature is a macroscopic phenomenon, in that it doesn't really make sense to talk about the temperature of a single particle. Once you have a collection of particles then you can. This is where the distinction between kinetic energy and temperature of molecules comes in. Suppose you have a jet of cold air. All the air moves at pretty much the same speed, that defines the speed of the jet. The temperature is defined from the point of view of someone moving with the jet of air and is due to the motion the particles have due to their thermal 'jiggling'. The fact the jet carries a lot of kinetic energy doesn't automatically mean it is hot. Suppose now you point this jet of cold air at a brick wall. The jet's motion is blocked, it slams into the wall. In doing this the nice 'coherent' motion of the air particles is converted into essentially random motion in all directions. This equates to the gas heating up, despite the fact the same kinetic energy is in the system. Heat equates to the particles of the material hitting one another (and other objects) quickly and often. The faster they move the harder and the more often they collide and the hotter it seems. I don't see what you're referring to. Do you mean conduction? Yes, different molecules require different temperatures and pressures to be liquids or solids or gases, which are controlled by the space they occupy and their energy content.
“ Originally Posted by darbarree If heat is energy, could we say that induction is infact simplly changing the energy levels trying to reach a state of eqealibrium which is more or less balancing the energy levels and 'heat' is a way of 'seeing' this? I don't see what you're referring to. Do you mean conduction? yes sorry i meant conduction, to much reading maybe Please Register or Log in to view the hidden image!
Just to elaborate on this, because it is essentially correct, Temperature is a distribution of the momentum of a large number of molecules. So if all you had was one molecule you can have it's momentum, but not a 'temperature' to speak of. (Though you could take it's momentum and figure the average temperature of objects with similar momentum and then assign it a 'temperature' but doing so would not be technically correct.)
You can't measure the "temperature" of a single molecule because temperature is a mean, and there is no mean energy or velocity for less than 2 molecules. However even a single molecule will reach equilibrium with the environment, and so be at the same temperature. So Szilard's engine is also a way to bring a single molecule to the same temperature as the container its in.
