1. The problem statement, all variables and given/known data Why has the Boltzmann's constant been defined? I know that the kinetic energy of a system is directly proportional to its absolute temperature, and that the proportionality constant is the Boltzmann's constant. But does the kinetic energy include all forms, i.e. rotational, vibrational, translational? Also, why should this ratio be always cosntant no matter what the system? 2. Relevant equations N/A 3. The attempt at a solution No idea! Any help would be greatly appreciated.