Which two statements are true about a system? A) All systems are made by humans. B) A system is a group of objects analyzed as one unit. C) Energy that moves across system boundaries is conserved. D) There’s only one way to define the boundaries of a system.
The Correct Answer and Explanation is:
The correct answer is B) A system is a group of objects analyzed as one unit and C) Energy that moves across system boundaries is conserved.
Explanation:
B) A system is a group of objects analyzed as one unit:
This statement is true because in scientific contexts, a system is typically defined as a collection of related objects or components that are considered together for the purpose of analysis. These objects interact with one another, and the boundaries of the system are established based on the focus of the study. For example, in thermodynamics, a system might refer to a gas inside a container, where the gas molecules are considered as the “objects” under observation.
By treating a system as a group of interacting components, we can better understand its behavior, interactions, and overall properties. The system’s boundaries are defined depending on the analysis being conducted, but the internal components are studied as a unified whole, which helps in simplifying complex phenomena.
C) Energy that moves across system boundaries is conserved:
This statement is also true and relates to the principle of energy conservation. In physics, particularly in thermodynamics, energy is conserved within a system, but energy can be exchanged with the surroundings. For instance, if heat is transferred from the system to the surroundings, or work is done by the system, the energy within the system decreases accordingly. However, the total energy—whether within the system or in the surroundings—remains constant. This is a direct application of the First Law of Thermodynamics, which states that energy cannot be created or destroyed, only transformed.
Why the other options are incorrect:
A) All systems are made by humans:
This statement is false because not all systems are human-made. Many natural systems, such as ecosystems, weather systems, or planetary systems, exist independently of human creation. Systems can be either natural or artificial, and the concept of a system is not limited to those that are human-engineered.
D) There’s only one way to define the boundaries of a system:
This statement is false because the boundaries of a system can be defined in multiple ways depending on the focus of the study. For example, a system could be defined to include certain objects or exclude others, based on what is relevant to the analysis. Different perspectives may lead to different definitions of what constitutes the system and its boundaries.
