What are open and closed systems?

1. What are open and closed systems? I can describe a system based on inputs, outputs and boundaries. I can defend whether a system is open or closed.

2. Two or more parts, working together, to perform a function. • Matter and energy flow through systems. Remember the definition of a system…

3. Two or more parts, working together, to perform a function. • Matter and energy flow through systems. • Input– An input is something that enters the system. It can be matter or energy. • Output– An output is something that leaves the system. It can be matter or energy. • Subsystem – a subsystem is a system that is part of another system. It’s a system within a system. • Boundary – the outside border of a system Adding to our definition…

4. In order to carry out their purpose, systems need an input of some kind. • Matter • Energy Input…

5. Outputs from a system can include: • Matter • Energy Sometimes the output from one system can become the input for another system. Output…

6. Open and closed systems…

7. An open system is a system in which both matter and energy can enter and leave. • What kinds of energy are inputs and outputs for this system? • What kinds of matter are inputs and outputs for this system? Open Systems

8. In a closed system, matter cannot enter and leave. • Only energy can enter and leave. • What kinds of energy are inputs and outputs for this system? • Why can’t matter enter or leave the system? Closed Systems

9. Open or Closed? Why?

10. Open or Closed? Why?

11. When the boundaries of a system change, the system can become open or closed • Boundaries can physically change, for example when part of a forest is cut down or a container is sealed. • We can change boundaries when we want to study a smaller or larger aspect of the system. Boundaries can change…

12. The soda can is a closed system. Change the boundaries… The soda can becomes an open system.

13. Plants are open systems. They have parts that help them survive and grow. They input energy – light, and matter – water, carbon dioxide, minerals. They output, or give off, matter - oxygen, new leaves …

14. If the boundary is expanded to include the whole terrarium that the plant is a part of, then we are studying a closed system. • Light and heat energy can flow, into and out of, the system. No matter can leave or enter the terrarium. Change the boundaries…

15. Think of a system. • Decide if it’s open or closed and write down your reasons. • Change the boundaries you used to define your system. • Decide if it’s open or closed and write down your reasons. Pick a system…

16. Based on “Teaching Systems as a Framework for Understanding”. Martha Mather and Vicky Smoot, NSTA Area Conference, Dec. 2011.