Question

How is the first law of thermodynamics derived?

Answer 1

Explanation:

According to the First Law of Thermodynamics, heat is a type of energy, and so thermodynamic processes are subject to the principle of energy conservation. This means that neither heat energy nor cold energy can be created or destroyed. However, it may be moved from one location to another and transformed to and from other types of energy.

1. The link between internal energy, work, and heat is described by the first law of thermodynamics. A system's internal energy can be increased in one of two ways: By working on the system. By providing the system with heat.
2. Let the system's internal energy to be $U_1$.
3. If it absorbs $q$ degrees of heat, its internal energy becomes $U_1+q$.
4. If more work is done on the system, the internal energy will increase to $U_1+q+w$.
5. Let us refer to this final internal energy as $U_2$, then the internal energy changes are depicted as follows,' $U_2-U_1=q+w$' can alternatively be written as $U=q+w$.
6. The formulation of the first law of thermodynamics is given above.

Hence, this is how the first law of thermodynamics is derived.