systems The lessexciting but stillinformative website version Systems

systems The less-exciting but stillinformative website version.

Systems • Definition: a group of objects working together for one purpose. • Systems can tell you what is causing other things to happen. • Example: adding a new objects to the group causes a new reaction. • Conclusion: the new object changes the system. • Adding wolves to Yellowstone

Systems in terms of energy • Adding a new object to the system changes the flow of energy. • A rollercoaster’s energy transformation begins with kinetic energy and transforms to potential and back again. • Let’s say a computer is needed to start the rollercoaster. Now it begins with electric energy, moves to electromagnetic energy and then becomes kinetic and potential energy.

Closed v. Open systems In a closed system, energy stays inside the system In an open system, energy flows to the surroundings Closed system: heat, energy, and matter is NOT exchanged with surroundings Examples: circulatory system, computer system Open system: heat, energy, and matter CAN BE exchanged with surroundings Examples: solar system, Wikipedia

Closed v. Open systems • Examples of a closed system: – Greenhouse – Water cycle • Examples of an open system: – Car emitting exhaust – Bunny

The ultimate closed system • The universe is a closed system. • There is a finite amount of energy in the universe. • No more energy can come in or leave the universe – Kind of like Hotel California • THE FIRST LAW OF THERMODYNAMICS (aka The Law of Conservation of Energy): Energy cannot be created or destroyed, merely transformed from one type to another.

Systems and energy When you know the boundaries of your system, you can trace where energy goes You can redefine your boundaries depending on what you are looking for. Practice! Find 3 examples of closed systems. For each: 1) justify why it is closed. 2) trace the path of energy in this system. Do the same for 3 examples of open systems. Ideas: any appliance you plug into the wall, open cabinet, a forest, classroom, the human body, a drinking fountain.