iScience said:internal energy U=q+W
so far we've only been substituting -PV into W but i just wanted to be sure that the W is the total work and not just the work done by the pressure right?
Internal energy is the total energy contained within a system, including the kinetic and potential energy of all its particles. In thermodynamics, it is used to describe the energy of a system that is not in motion or undergoing any changes in temperature, pressure, or volume.
Internal energy is directly proportional to temperature. As the temperature of a system increases, so does its internal energy. This is because an increase in temperature leads to an increase in the average kinetic energy of the particles in the system.
Yes, internal energy can be converted into work. This is known as the first law of thermodynamics, which states that the change in internal energy of a system is equal to the heat added to the system minus the work done by the system. This means that if heat is added to a system, its internal energy will increase, and this energy can be used to do work.
Internal energy is affected by changes in pressure and volume through the work done by the system. If the volume of a system increases, the system must do work against the external pressure, resulting in a decrease in internal energy. Similarly, an increase in external pressure causes the system to do work, leading to a decrease in internal energy.
Enthalpy is the sum of a system's internal energy and the product of its pressure and volume. It is often used in thermodynamics to describe the heat content of a system at constant pressure. While internal energy is the total energy of a system, enthalpy takes into account the energy required to do work against the external pressure and is therefore useful in analyzing systems undergoing changes in volume.