The First Law of Thermodynamics states:
A. energy can be changed from one form to another, but cannot be created or destroyed
B. energy is constantly being created by entropy events
C. energy can be used and then destroyed because of entropy’s actions on it
D. energy can be destroyed while it is producing entropy
The correct answer and explanation is:
The correct answer is:
A. energy can be changed from one form to another, but cannot be created or destroyed
Explanation:
The First Law of Thermodynamics, also known as the Law of Energy Conservation, states that the total energy of an isolated system remains constant. This means energy cannot be created out of nothing or destroyed into nothing; instead, it can only change from one form to another.
For example, when you burn gasoline in a car engine, the chemical energy stored in the fuel is converted into mechanical energy (motion) and heat. The total amount of energy before and after this process remains the same; it has just transformed from chemical energy into other forms.
This principle is fundamental in physics and engineering because it allows us to analyze energy flow and conversion in systems, from engines and refrigerators to living organisms. It guarantees that energy accounting always balances: energy input equals energy output plus any changes in stored energy.
Why other options are incorrect:
- B. energy is constantly being created by entropy events:
This is false because energy is never created; entropy describes disorder or energy dispersal, not creation of energy. - C. energy can be used and then destroyed because of entropy’s actions on it:
This is incorrect. Entropy causes energy to become less available for useful work (like spreading heat), but it does not destroy energy. The total energy remains constant. - D. energy can be destroyed while it is producing entropy:
This is also false. Energy is conserved regardless of entropy changes. Entropy affects how energy is distributed and its quality (usefulness), but it does not destroy energy.
Summary:
The First Law of Thermodynamics confirms the fundamental principle of energy conservation: energy can neither be created nor destroyed but only transformed. This principle underpins all energy analysis in science and technology. Entropy, often discussed alongside this law, affects how energy can be used but never negates the conservation of energy itself.