1. What are system inputs and outputs? What is a system boundary? I can describe the components of a system. I can describe a system based on inputs, outputs and boundaries.

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

3. Input… Energy in some form is an input of a system. Matter can also be an input.

4. Input is motion energy.

5. Output… Energy in some form is an output of a system. This is usually the function of the system Matter can also be an output.

6. The output is also motion energy. Are there any other energy outputs?

7. Identify the parts, the input and the output.

10. Adding to our definition… 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.

11. Sometimes the output from one system can become the input of another system. One output from the person (system) is the energy that is the input of the bicycle system.

12. What output may also be an input?

14. Adding to our definition… 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.

15. What are the subsystems?

16. Boundary – the boundary is the outside border of the system. Depending on where we draw the boundary we can study a system or a subsystem. This boundary includes both the boy and the skateboard in the system. Change the boundary to only study the skateboard system.

17. Why? Because we look at things systematically to understand them. Sometimes we look at the larger system, and sometimes we look at the smaller system that is actually the subsystem of a larger system.

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