Average kinetic energy/ temperature confusion

1. Apr 22, 2014

Bengo

My mcat book says temperature is a measure of the total kinetic energy of a system. Then later on it says temperature is a measurement of the average kinetic energy of a system. Is this an error? Thank you.

2. Apr 22, 2014

PhysicoRaj

The second statement is correct. The first one refers to heat content.

3. Apr 22, 2014

Bengo

Are average kinetic energy and temperature the same thing?

4. Apr 22, 2014

Yanick

In a given system of particles at a given temperature their is a distribution of kinetic energies, some are slower and some are faster. Classical mechanics, and some statistics, can be used to relate the average kinetic energy of the system to the temperature of the system. You can read some more about this if you check out the Kinetic Theory of Gases. Without more details regarding the statement we cannot rule either statement out as incorrect because the higher the average kinetic energy the higher the total kinetic energy which are in fact proportional to the temperature. Don't forget that averages are sums divided by the population of the sample. So total kinetic energy is the sum of the kinetic energies of the particles and the average KE differs from the total by a constant (the number of bodies). In the context of the gross oversimplification related to physical science training of healthcare providers we can say that each statement is correct.

5. Apr 22, 2014