Internal energy is the total energy of a system, including both its kinetic and potential energy. It is a measure of the microscopic energy of the particles that make up a system.
The first law of thermodynamics, also known as the law of conservation of energy, states that energy cannot be created or destroyed. It can only be transferred or converted from one form to another.
The first law of thermodynamics is essentially a statement about the conservation of internal energy. In any thermodynamic process, the change in internal energy of a system is equal to the heat added to the system minus the work done by the system.
A P vs V graph is a graph that plots the pressure (P) of a gas on the y-axis and the volume (V) of the gas on the x-axis. This type of graph is commonly used in thermodynamics to visualize the relationship between pressure and volume in a system.
The first law of thermodynamics can be represented on a P vs V graph by the area under the curve. The work done by the system is equal to the area under the curve, while the heat added to the system is represented by the change in the internal energy of the system.