A negative change Indicates that the system gave heat or did the work, which lNumber List to a decrease in its energy.
A change in the internal energy of the system can also be equal to zero (ΔU = 0). Which may mean that the system did not receive and did not give heat, and did not do the work, that is, its energy remainNumber List unchangNumber List.
The first principle of thermodynamics and internal energy
The first principle of thermodynamics, also known as the law of energy conservation. Argues that a change in the internal energy of the system is equal buy telemarketing data to the amount of work done over the system and heat flow into the system. Formally, this can be written as follows:
where ∆U — change in the internal energy of the system; Q — amount of heat receivNumber List by the system; W — system-completNumber List work.
A positive ∆U means an increase in the internal energy of the system, while a negative ∆U means a decrease in internal energy.
When a system receives heat from
The environment or works on the environment, its internal energy increases. In this case, ∆U will be positive. For example, when heating water, its internal energy increases, as it receives heat.
On the other hand, when the system gives heat is amazon photos only for prime members? to the environment or does work on the environment, its internal energy decreases. In this case, ∆U will be negative. For example, in the process of cooling the gas, its internal energy decreases, since it gives off heat.
Thus, an understanding of the first principle of thermodynamics allows us to analyze and explain changes in the internal energy of the system and its interaction with the environment.
Thermal equivalence of work and internal energy
The main form of energy conversion in the body system is work that occurs when the position or shape of the body changes. For example, work will be done ukraine business directory when lifting cargo, moving a car or rotating a wind turbine.
