Temperature
Temperature and Kinetic Energy
When matter is in motion, it possesses kinetic energy.
If a body has mass M and velocity v, its kinetic energy is given
by the formula
E=1/2(mv2).
Heat is
a familiar form of energy, and in bulk materials
(solids, liquids, or gases) this heat is stored in the form of the
kinetic energy of the molecules. How much heat a body contains determines
how 'hot' or 'cold' it feels. A body at high temperature contains more
heat than the same body at low temperature.
This is the same as saying the molecules within have either high or low average
kinetic energy.
Kinetic energy can be exchanged between bodies during collisions.
So heat is exchanged between bodies by the collision between their molecules. This is the transport of heat by conduction so it's obviously necessary for
molecules to move for heat to be transported in this way.
The temperature in a system is related to the kinetic energy by
the formula
<1/2(mv2)> = 3/2(kT)
where k is Boltzmann's constant,
and the <> indicate an emsemble average (or equivalently, in this case) over all the molecules in the system.
