Energy Transfer

1. Energy Energy Transfer Zap!

2. What is Energy? • (physics) the capacity of a physical system to do work; the units of energy are joules or ergs; "energy can take a wide variety of forms" • Work: When a force acts to move an object, we say that Work was done on the object

3. Thermodynamics is the study of energy. • First Law of Thermodynamics: Energy can be changed from one form to another, but it cannot be created or destroyed. The total amount of energy and matter in the Universe remains constant, merely changing from one form to another. • The Second Law of Thermodynamics states that "in all energy exchanges, if no energy enters or leaves the system, the potential energy of the state will always be less than that of the initial state." This is also commonly referred to as entropy. • E.X. A watchspring-driven watch will run until the potential energy in the spring is converted, and not again until energy is reapplied to the spring to rewind it. A car that has run out of gas will not run again until you walk 10 miles to a gas station and refuel the car.

4. LAW • In physics, the law of conservation of energy states that the total amount of energy in any isolated system remains constant but cannot be recreated, although it may change forms, e.g. friction from rubbing your hands together turns kinetic energy into thermal energy.

5. Two Types of Energy • Potential Energy: Potential energy can be thought of as energy stored within a physical system • Kinetic Energy: Kinetic energy is the energy of motion. An object which has motion - whether it be vertical or horizontal motion

6. 5 Forms Of Energy(there are many forms but these will do for our purposes.) • Solar • Thermal • Mechanical • Electric • Chemical

7. Solar • Solar energy is energy directly from the Sun.

8. Thermal Energy • Thermal energy is the energy portion of a system that increases with its temperature. In a loose sense, "thermal energy" is a term used to describe the energy content of a system related to heating effects, e.g. temperature increase or decrease.

9. Mechanical Energy • In physics, mechanical energy describes the potential energy and kinetic energy present in the components of a mechanical system (moving parts). • E.X. a car has many different mechanical energy systems in it.

10. Electric • The electric energy is the potential energy associated between charged particles (i.e. electrons) contained within a system.

11. Chemical • Chemical energy is the greatest source of energy used by man. From flashlight batteries to commercial airlines, it is the energy released from chemical reactions. Paradoxically, most of the electricity produced in the world comes from the chemical energy released in the burning of coal, oil and gas.

12. Energy Transfer Example

13. Practice Solar Electric Electrical/Thermal Chemical Chemical Chemical

14. Energy transfer all around us! • Ecosystem level energy transfer

15. Powerful Classroom Assessment: Aquarium Systems Attributes of a Description for Awarding Value Points

16. Rubric for Write a Conclusion Items

17. Write Conclusions to Investigations A technique seen during scoring the 2006 G5 Science WASL X vs. Y

18. Powerful Classroom Assessment: Aquarium Systems Item 10: Plan an Investigation (continued)

19. Powerful Classroom Assessment: Aquarium Systems Item 10: Plan an Investigation (continued)