Question

Is the weight of a system an extensive or intensive property?

Short answer

Explain your reasoning. Answer: The weight of a system is an extensive property as it depends on the mass of the system. Mass is an extensive property because it depends on the amount of substance present in the system. Thus, since weight is related to mass, it also depends on the amount of substance, making it an extensive property.

Step-by-step solution

Understand Extensive and Intensive Properties

Extensive properties are those that depend on the amount of substance present in the system, such as mass or volume. In contrast, intensive properties are independent of the amount of substance and depend only on the type of substance, such as temperature or pressure.

Analyze Weight as a Property

The weight of a system can be defined as the force experienced by an object due to gravity. As it is related to the mass of the system and mass is an extensive property, we can deduce the relationship between weight and the amount of substance in the system.

Determine if Weight is Extensive or Intensive

As the weight of a system depends on its mass (which is an extensive property), it also depends on the amount of substance present in the system. Therefore, the weight of a system is an extensive property.

Key concepts

Thermodynamics

At its core, thermodynamics is the branch of physics that deals with the relationships between heat and other forms of energy. In essence, it studies how thermal energy is converted to and from other types of energy and how it affects matter.

Thermodynamics revolves around several principles known as the laws of thermodynamics which govern the flow of energy and the work it can perform. A key part of understanding these principles is grasping the various properties of materials, which are often categorized as either extensive or intensive properties.

These properties play a crucial role in how substances interact with energy and are fundamental concepts for any student studying thermodynamics, whether they’re analyzing a steam engine's efficiency or the enthalpy changes in a chemical reaction.

Extensive Property

An extensive property is a physical quantity that changes when the size of the system changes. Essentially, it 'extends' with the system. Examples of extensive properties include volume, mass, and energy. They are additive for subsystems, meaning that the total value for the entire system is the sum of its parts.

Understanding Extensive Properties

When considering extensive properties, think of a block of metal: if you cut it into two pieces, properties like mass and volume will also be divided into two, reflecting the change in the system’s scale. In the context of a homework exercise or understanding physical systems, extensive properties are vital for determining how systems interact when combined or divided.

Intensive Property

On the flip side, an intensive property is characteristic of a material that doesn't change with the amount of the substance. These properties are intrinsic to the substance, such as temperature, boiling point, and pressure.

Distinguishing Intensive Properties

Consider the same block of metal mentioned earlier. If you measure its temperature or boiling point, these properties will remain the same regardless of how many pieces the block is divided into. Intensive properties are particularly useful when identifying a substance or comparing the properties of substances at different scales. A common educational task would be to classify given material properties as either intensive or extensive, which enhances the understanding of material characteristics and thermodynamic principles.

System Weight

The concept of a system's weight is crucial in the real-world application of thermodynamics and physics. Weight is defined as the force generated by gravity on any object with mass. Since the weight of an object is directly proportional to its mass, and as mentioned earlier, mass is an extensive property, the weight of a system is also extensive.

Practical Implications of System Weight

Why is it extensive? Simply put, if you have two identical systems with identical masses, their combined weight will be double that of one system because weights are additive. In any scientific problem-solving scenario, recognizing weight as an extensive property helps predict how systems will respond to physical changes and interplay with gravitational forces, providing a foundational understanding for more complex physical and engineering calculations.