Degree of Freedom
It is the ability of a gas
molecule which can move freely with respect to the available circumstances.The
degree of the freedom of a gas molecule depends on the nature of the gas
molecule.
The molecule of a mono atomic gas
can have only translatory motion and hence it has 3 degree of the freedom along its
x-axis y-axis and z-axis.
Diatomic gas molecule can have
not only a translatory motion but also rotatory motion along two other
possible axis. Thus it can have five degrees of freedom.
Tri/poly atomic gas molecule can
have translatory motion, vibratory motion as well as a rotatory motion.
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Law of the Equipartisien energy:
As per this law the average
kinetic energy per each degree of the freedom per molecule is fixed.
Basing on this concept we can
find the specific heat of a gas at constant volume, at constant pressure and
the ratio of their specific heats as shown below.It can be also proved easily
that in all the supplied heat energy of hundred percent,around 60% is used to
increase the internal energy in the case of mono atomic gas.
Basing on the law of Equipartisien energy we can also find the
ratio of the specific heats of the gases at constant pressure and volume and it
can be proved that about the total heat energy supplied around 71% is used to
increase its internal energy and the remaining 29% is used to do the additional
work.
As per the law of Equipartisien
energy we can find the ratio of the specific heat of the gases for tri atomic
gas at constant pressure and volume as shown below. It can we also proved that
out of the total supplied heat energy 75% of the heat energy is used to
increase the internal energy and only the remaining 25% is used to do the
external work.
Distance and displacement comparison
