Final answer:
The configuration described is an isolated system, as there is zero net external force acting on it and its mass remains constant, which allows for conservation of linear momentum and simplifies the application of mechanics principles. The correct answer is C.
Step-by-step explanation:
A student has asked about the type of system represented by three 150 g masses connected by massless, rigid rods. This configuration is an example of an isolated system because it meets the definition of an isolated system, which states that there must be zero net external force acting on it and its mass remains constant.
The term isolated system is often used in physics to describe a system where no matter or energy is exchanged with the environment. For a system of particles to be considered isolated, it must be free of external forces and must not lose or gain mass. In this case, assuming that there are no external forces (like gravity or friction) acting on the system and no mass is being added or removed, the system of masses and rods would conserve its total momentum, fulfilling the criteria of an isolated system.
Systems in physics can also be categorized as open or closed. An open system can exchange mass and energy with its surroundings, whereas a closed system can exchange energy but not mass. Given that the system described does not allow for the transfer of either mass or energy, it is not open or closed but truly isolated.
In applications, such an isolated system allows us to apply the conservation of linear momentum and other conservation laws without considering external influences. This is a simplification often used in theoretical and practical problems to understand fundamental principles of mechanics and motion.