Final answer:
Examples of physical systems include a windmill, the gears of a clock, and the digestive system of a cow. A scientific theory, however, is not a physical system.
Step-by-step explanation:
All of the following options are examples of physical systems:
- A) a windmill: A windmill is a mechanical device that converts wind energy into rotational energy to perform a specific function, such as grinding grain or generating power.
- C) the gears of a clock: The gears of a clock form a physical system that work together to control the movement of the clock's hands.
- D) the digestive system of a cow: The digestive system of a cow is a complex physical system that allows a cow to break down and absorb nutrients from its food.
B) a scientific theory: A scientific theory, on the other hand, is not a physical system. It is an explanation or model based on observed facts, experiments, and reasoning that helps us understand and predict natural phenomena.