Strictly speaking, your textbook is the better, and more common, definition.princejan7 said:Wikipedia says its the TOTAL energy contained by a thermodynamic system.
But the textbook says
Total energy = internal energy + kinetic energy + potential energy
In thermodynamics, the internal energy is the total energy contained by a thermodynamic system. It is the energy needed to create the system but excludes the energy to displace the system's surroundings, any energy associated with a move as a whole, or due to external force fields.
Internal energy is the sum of all the microscopic forms of energy in a system. It includes the kinetic energy of molecules, the potential energy of intermolecular forces, and the energy stored in chemical bonds.
Heat is the transfer of energy between two objects due to a temperature difference. Temperature is a measure of the average kinetic energy of molecules in a substance. Internal energy, on the other hand, is the total energy contained within a system.
The internal energy of a system can be affected by changes in temperature, pressure, volume, and the number of particles in the system. It can also be influenced by the type of substance and its chemical composition.
Yes, internal energy can be measured using thermodynamic techniques such as calorimetry or by directly measuring the changes in temperature, pressure, and volume of a system.
Internal energy can change through two processes: work and heat. Work is the transfer of energy due to a force acting on a system, while heat is the transfer of energy due to a temperature difference. Both work and heat can increase or decrease the internal energy of a system.