first law of thermodynamics
Học thuậtThân thiện
Definition
- Noun:
- The fundamental principle of physics that the total energy of an isolated system is constant despite internal changes: This law states that energy cannot be created or destroyed in an isolated system; it can only be transformed from one form to another or transferred between parts of the system.
Usage Examples
- Noun:
- The first law of thermodynamics is a statement of the conservation of energy.
- When calculating the efficiency of an engine, one must apply the first law of thermodynamics.
- A common formulation of the first law of thermodynamics is that the change in a system's internal energy is equal to the heat added to the system minus the work done by the system.
Advanced Usage
- "to be consistent with the first law of thermodynamics": to not violate the principle of energy conservation.
- Any proposed perpetual motion machine must be checked to see if it is consistent with the first law of thermodynamics.
- "an expression of the first law of thermodynamics": a specific mathematical or verbal formulation of the law.
- The equation ΔU = Q - W is a common mathematical expression of the first law of thermodynamics.
Variants and Related Words
- Law of conservation of energy (noun phrase): A closely related principle, often used synonymously in many contexts, stating that the total energy of an isolated system remains constant.
- Thermodynamics (noun): The branch of physical science that deals with the relations between heat and other forms of energy.
- Internal energy (noun phrase): A key concept in the law, referring to the total energy contained within a system.
Synonyms
- Conservation of energy principle: The principle that energy is conserved.
- Energy conservation law: A law stating that energy is neither created nor destroyed.
Related Phrases
- First law (shortened form, noun phrase): A common abbreviation used in technical contexts where "thermodynamics" is implied.
- According to the first law, the net energy transfer is zero for that cycle.
Noun
- the fundamental principle of physics that the total energy of an isolated system is constant despite internal changes