Reporting Category: Fluid and Thermal Systems Standard: 3.1 - Explain the basic differences between open fluid systems (e.g., irrigation, forced hot air system, air compressors) and closed fluid systems (e.g., forced hot water system, hydraulic brakes).
Fluid systems may be open systems or closed systems.
Contrast an open fluid system with a closed fluid system.
Provide one example of a closed system that contains a liquid.
Identify whether the type of fluid in open systems is always liquid, is always gas, or can be either liquid or gas. Provide two examples to support your answer.
In a particular closed fluid system a liquid exerts a force of 360 lb. on a piston with a cross-sectional area of 12 sq. in.
Calculate the pressure of the liquid in the system. Show your calculations and include units in your answer.
Scoring Guide and Sample Student Work Select a score point in the table below to view the sample student response.
The response demonstrates a thorough understanding of the differences between open fluid systems and closed fluid systems. The response correctly contrasts an open fluid system with a closed fluid system and provides an example of a closed system that contains a liquid. The response correctly identifies that the type of fluid in open systems can be either liquid or gas and provides two examples to support this. The response also correctly calculates the pressure of the liquid in the system.