The internal energy U of a system is defined as the sum of the energies of all the constituent particles. The internal energy of an ideal gas does only depend on the temperature and the number of particles, and not on the volume occupied by the gas. Let us carry out an experience to confirm this statement.
An experience will be performed to help understanding the differences between the internal energy U and the temperature T of a system.
Two systems are shown made up of particles of the same mass. With the "CONTROL PANEL" we can control the number of particles and the energy of each system, and therefore its temperature.
Experiment with the internal energy U of the systems and the number of particles in each system and observe their correlation with the temperature T.