Chapter 2 Science, Matter, Energy and Systems (Part 1-2) PDF

Science, Matter, Energy and Systems CHAPTER 2 – Part 2 Understanding and Managing Systems Open and Closed Systems: It’s a matter of inputs and outputs When you hear the word “system”, what words or images come to mind? Examples that come to mind… solar system, digestive system,...

Science, Matter, Energy and Systems CHAPTER 2 – Part 2 Understanding and Managing Systems Open and Closed Systems: It’s a matter of inputs and outputs 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’s 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. 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…. What we know… A system is two or more individual parts working together for a common function (purpose) that combine to form a whole. Systems are similar because they are made up of several parts; if one of these parts changes, it impacts the entire system. However the purpose of the systems, and their inputs and outputs, are different depending upon what you are studying. SYSTEM INPUT SYSTEM OUTPUT Any energy or matter that comes Any energy or matter that leaves a into a system system and is a product of a system We know about inputs and outputs inputs— things that get put in to make the system function (not a part of the system). outputs— stuff that gets put out of a system, sometimes what they do, and sometimes other things (not a part of the system). What kind of energy input is needed by these systems? Reminder: Inputs In order to carry out their purpose, systems need an input of some kind of: – Energy – Matter – Information Forms of Energy Input What kind of energy input is needed by these systems? Reminder: Outputs Outputs from a system can include: – Energy – Matter – Information Remember: Inputs can become Outputs Sometimes the output from one system can be an input for another system. That brings us to Open and Closed Systems We can describe systems as being open or closed. 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. CLOSED SYSTEM OPEN SYSTEM Surroundings Exchange of matter with the surroundings Exchange of energy with the surroundings 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? 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? Subsystems A subsystem is a system that is part of another system. It’s a system within a system. Subsystems How do we find the boundaries of a system? Example: The boundaries The bicycle seat, frame, wheels, brakes, of a system is lights, etc… it’s all one physical part together…if you take away one wheel determined by now it’s a unicycle not a bike…. the question you ask and how the systems parts work together The boundaries define the system and what you’re studying.  Boundaries can change Boundaries can physically change, like when a part of a forest is cut down We can change boundaries For example, a doctor might consider your whole body system to see if you when we want to think are healthy overall, or just look at your about just part of a system. throat if you have a sore throat. How can systems change? When their boundary changes, they can become open or closed. Changing Boundaries: Example Physical Boundary Change Picture of forest with road through it. Closed can become open; open can become closed The closed system becomes open when an opening is created in the actual physical boundary. Closed can become open; open can become closed Plants are open systems. They have parts to help them survive. They take in light energy, plus matter (water and carbon dioxide and minerals) and give out matter (oxygen, new growth, leaves, fruit). 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 Completed ecosystem in a bottle from science kit. Stump a friend Take a minute and think of an example of a system that is open or closed. Why do you think it is open or closed? Now, ask your friend about your system. Do they agree or disagree? How can you decide who is correct? Why use systems? ▪ Because the universe is complex and gigantic. ▪ So, scientists break things into smaller units they call “systems”. That way, they don’t have to try to study everything at once. They can look at it system by system—or systematically. Thank you!