What does average kinetic energy mean?

Answer 1

Instead of the precise value of the kinetic energy of a system, for example a gas, it is generally more useful to consider its average kinetic energy, since it is absolutely impossible to measure the velocities of all the molecules: <E_k>=1/2 m<v^2>, where <> denotes the mean of the quantity in brackets. More importantly, the average kinetic energy has a very important physical interpretation: it is proportional to the temperature of the system. Temperature itself can be defined as a measure of the kinetic component of the internal energy of a system: according to the equipartition theorem, each independent quadratic energy term corresponds to an average energy of 1/2 kT, where k is Boltzmann's constant; so, in three dimensions the mean kinetic energy of a molecule is 3/2 kT.

Answer 2

Average kinetic energy refers to the average energy possessed by the particles of a substance due to their motion. It is directly related to the temperature of the substance, with higher temperatures corresponding to higher average kinetic energies. This energy is a form of thermal energy that contributes to the overall heat of a system.