Understanding the First Law of Thermodynamics and Energy Transformation

The question asks us to complete a sentence describing the First Law of Thermodynamics by selecting the most appropriate word from the given options. The sentence highlights a key aspect of this fundamental law: energy can change its form but is not created or destroyed.

Let's analyze the provided sentence:

"The first law of thermodynamics states that whereas energy can be ____________ from one form into another, it cannot be created or destroyed."

The blank space requires a word that accurately describes the process of energy changing from one form (like potential energy) to another (like kinetic energy, heat energy, etc.).

Analyzing the Options

Let's look at each option and evaluate its suitability:

• reduced: This word means to make something smaller in amount, extent, or size. While energy values might decrease during inefficient transformations (with some energy being lost as unusable heat), the core principle is not about reducing the total energy but changing its form. So, "reduced" is not the correct word to describe the change in form.
• induced: This word means to bring about or give rise to something. While a process can induce energy transformations, "induced" itself doesn't describe the act of changing form. It's more about causing the change rather than being the change itself.
• performed: This word means to carry out, accomplish, or fulfill an action. Energy transformations are processes that are "performed" by systems, but energy itself isn't "performed" from one form to another. The word describes the action, not the transformation process of the energy.
• transformed: This word means to make a thorough or dramatic change in form or appearance. In physics, particularly in thermodynamics, "transformed" is the standard term used to describe energy changing from one type (like chemical potential energy) to another (like thermal energy or mechanical work). This perfectly fits the context of the sentence which states energy changes "from one form into another."

The Correct Word for Energy Change

Based on the analysis, the word that precisely describes energy changing "from one form into another" is "transformed". The First Law of Thermodynamics is often summarized by saying that energy is conserved; it can be transformed from one type to another but the total amount remains constant in a closed system.

Therefore, the completed sentence should read:

"The first law of thermodynamics states that whereas energy can be transformed from one form into another, it cannot be created or destroyed."

Revision Table: Evaluating Options

Additional Information: The First Law of Thermodynamics

The First Law of Thermodynamics is a version of the law of conservation of energy, adapted for thermodynamic systems. It states that energy cannot be created or destroyed, but it can be transferred or changed from one form to another.

Mathematically, the First Law is often expressed as:

\( \Delta U = Q - W \)

Where:

• \( \Delta U \) is the change in the internal energy of the system.
• \( Q \) is the heat added to the system.
• \( W \) is the work done by the system.

This equation shows that the change in internal energy of a system depends on the heat flowing into or out of the system and the work done by or on the system. This is a direct application of the principle that energy is conserved and transformed.

Understanding energy transformations is crucial in many areas of science and engineering, from power generation (e.g., converting chemical energy in fuel to thermal energy and then electrical energy) to biological processes (e.g., converting chemical energy in food into mechanical work and heat). The First Law of Thermodynamics provides the fundamental principle governing these transformations.