b) Describe three real life examples of an ideal close system.
A closed system, in the context of thermodynamics, refers to a system that does not exchange matter or energy with its surroundings. Here are three real-life examples of closed systems:
1. A thermos: A thermos is designed to limit heat transfer, keeping hot beverages hot and cold beverages cold. It is essentially a closed system that minimizes heat exchange with the external environment. The vacuum layer between the inner and outer walls of the thermos prevents heat exchange by conduction and convection, while the reflective interior surface minimizes radiation heat transfer.
2. A sealed jar of preserves: When fruits or vegetables are preserved in a sealed jar, it becomes a closed system for these food items. The jar prevents matter exchange (no air circulates in and out) and minimizes heat exchange. The heat is initially applied to sterilize the jar and its contents, so no further heat or matter exchange is required to preserve the food.
3. A space station: In space, space stations such as the International Space Station (ISS) are close to closed systems since they are isolated from the surrounding environment. Although some matter and energy exchange can occur through resupply missions and solar panels, a well-designed space station tries to minimize these exchanges to maintain life support systems and preserve resources as much as possible.
To identify examples of closed systems, one needs to consider whether matter (such as substances or particles) and energy (in the form of heat or work) can enter or leave the system. If no exchange of matter or energy occurs, or if it is highly restricted, then one can consider it a closed system.