Notes Systems

When you hear the word, “system,” what words or images come to mind? Examples that come to mind……solar system, digestive system, school system, stereo system, respiratory system, and muscular system What is a SYSTEM? Write your definition on your notes.

What is a System? A system is made up of different parts that come together to form a whole; a system is a collection of things and processes that interact to perform some function. A system has boundaries. A system has inputs and outputs.

Why do we use systems? The world around us is so complex. To study everything all at once in its entirety would be impossible and overwhelming….. So scientists break things down into smaller related parts that they can study more easily and we call these things systems….

Cedar Heights (as a System) The school as a SYSTEM Cedar Heights (as a System) teachers classes Sub-systems are parts of a system that work together for the system to function Education System Cedar Heights (as a sub-system)

Brainstorm as many components/parts of our school as possible Brainstorm as many components/parts of our school as possible. This would include living and nonliving parts. List your ideas:

What if one part was removed? Some components or parts are: principal, vice principal, secretaries, teachers, students, the building, buses, bus drivers, custodians, cafeteria staff, media specialists, guidance counselors, nurses, desks, books/supplies

How do we find the boundaries of a system? The boundary of a system is determined by the question you ask and how the parts of the system work together. Example: The bicycle….seat, frame, wheels, brakes, lights etc… it’s all one physical part together…if you take away one wheel now it’s a unicycle not a bike…. The boundaries define the system and what you are studying.

Boundaries can change Boundaries can physically change, like when part of a forest is cut down We can change boundaries when we want to think about just part of a system. For example, a doctor might consider your whole body system to see if you are healthy overall, or just look at your throat if you have a sore throat. Mather, Smoot, & Brager 2011

Any energy or matter that comes into a system SYSTEM INPUT: Any energy or matter that comes into a system SYSTEM OUTPUT: Any energy or matter that leaves a system is an output and a product of a system.

What kind of energy input is needed by these systems? Mather, Brager, and Smoot 2011

Inputs In order to carry out their purpose, systems need an input of some kind of Energy Matter Information. Mather, Smoot, & Brager 2011

Remember: outputs can become inputs Sometimes the output from one system can become the input for another system. Repeated image from second PowerPoint of dog with ears blown back by fan. Repeated from second PowerPoint—image of woman listening to iPod through headphones. Mather, Smoot, & Brager 2011

Open and Closed Systems: It’s a MATTER of inputs and outputs Mather, Smoot, & Brager 2011

Open vs. Closed Systems In open systems matter and energy may flow in and out of the system. In closed systems only energy flows in or out… the amount of matter stays the same.

Example: Open Systems An open system is a system in which both matter and energy can enter and leave. Information can also enter and leave. What kinds of energy are inputs and outputs for this system? What kinds of matter are inputs and outputs? First, verify with students that these meet the definition of a system. Mather, Smoot, & Brager 2011

Example: Closed Systems In a closed system, matter cannot enter and leave. Only energy and information can. What kinds of energy can enter and leave this system? Why can matter not enter or leave? Heat can enter and leave, so could mechanical energy through rolling, light bounces off the can and we can see it. Mather, Smoot, & Brager 2011

Closed can become open; open can become closed But if we expand our boundary to include the whole mini ecosystem that the plant is a part of, we are looking at a closed system. No matter can leave or enter the bottle ecosystem, though light and heat energy can. Completed ecosystem in a bottle from science kit. Mather, Smoot, & Brager 2011

Take a minute and think : Is the Earth an open or a closed system Take a minute and think : Is the Earth an open or a closed system? Now, ask your table partner. Do they agree or disagree? How can you decide who is correct? Mather, Smoot, & Brager 2011