September 13, 2010

1. September 13, 2010 Agenda • Types of Energy • Introduction of Unit Project Homework • Identify and describe 5 different renewable energy sources used to produce power to our homes BrainTeaser • Fossil fuels (coal, oil and gas) will eventually run out. Why are they called “fossil” fuels? • Why are they so important to our society?

2. Unit 3 Objectives • Understand how energy is stored in a system • Describe how energy is transferred from one system to another • Energy is conserved in a closed system

3. Energy: Forms and Changes

4. Nature of Energy • Energy is all around you! • You can hear energy as sound. • You can see energy as light. • And you can feel it as wind.

5. Nature of Energy • You use energy when you: • hit a softball. • lift your book bag. • compress a spring.

6. Nature of Energy Living organisms need energy for growth and movement.

7. Nature of Energy • Energy is involved when: • a bird flies. • a bomb explodes. • rain falls from the sky. • rollercoasters rise and fall • electricity flows in a wire.

8. A burning match releases energy. Source: ElektraVision/ PictureQuest

9. The sun is the source of all energy we use

10. Nature of Energy • What is energy that it can be involved in so many different activities?

11. Energy Expert Jigsaw • Begin by summarizing the information in the article that your group was assigned • Then form groups of 3—1 representative from each article group

12. List Energy types and sources • Use the notes that you made from your article group. • Make a list of at least 30 words of energy types and sources in your 3 person group

13. examples • Nuclear • chemical • gasoline • electricity • batteries • fusion • oil • Mechanical • kinetic • potential • natural gas • Steam • food • light • microwaves • hydro • Fission • thermal • sound • x-rays • heat • Uranium • wind • tides • hot water • gun powder • wound up spring toy • static cling • ball in motion • heavy water • hydro • solar • ultraviolet rays • turning drill bit • lightning • wood • stretched bungee cord • star light • heat lamp • stretched rubber band • charcoal • heavy water • compass

14. CHEMISTRY September 15, 2010

15. Warm Up • Name 5 sources of renewable energy.

16. September 14, 2010 Agenda • Warm Up • Collect Unit 2 Review: Period 5 • Unit 3: • The Law of Conservation of Energy • Energy Conversions • Information on Research Project Homework Energy Jigsaw Homework Begin Project Research

17. What IS energy? • Energy (E): The ability to do work or produce heat (units of Joules or KiloWatt hour) • Work (w): The capacity to move an object over a distance against a resisting force (units of Joules or Newton-meters)

18. What IS energy? • Because of the direct connection between energy and work, energy is measured in the same unit as work: joules (J). • In addition to using energy to do work, objects gain energy because work is being done on them.

19. What about POWER? • Power: the rate at which work can be done, i.e. a measure of how quickly work can be done (units of Watts) • Power is like the strength of a weightlifter, energy is like his endurance. The work the weightlifter does is moving the weights from the ground to over his head. • Can you think of other examples?

20. States of Energy • All forms of energy can be in either of two states: • Potential • Kinetic

21. Potential Energy • Energy due to the composition or the position of an object • Composition: type of atoms, number and types of chemical bonds and arrangement of the atoms • Position: objects waiting to fall off a shelf

22. Potential Energy • Potential Energy is stored energy. • Stored chemically in fuel, the nucleus of atom, and in foods. • Or stored because of the work done on it: • Stretching a rubber band. • Winding a watch. • Pulling back on a bow’s arrow. • Lifting a brick high in the air.

23. Potential Energy • Energy that is stored due to being stretched or compressed is called elastic potential energy.

24. Gravitational Potential Energy • Potential energy that is dependent on height is called gravitational potential energy.

25. Gravitational Potential Energy • A waterfall, a suspension bridge, and a falling snowflake all have gravitational potential energy.

26. Gravitational Potential Energy • “The bigger they are the harder they fall” is not just a saying. It’s true. Objects with more mass have greater G.P.E. • The formula to find G.P.E. is G.P.E. = Weight X Height.

27. Kinetic Energy • Kinetic • Energy of motion • moving objects, moving particles, vibrating molecules, etc

28. Kinetic Energy • The faster an object moves, the more kinetic energy it has. • The greater the mass of a moving object, the more kinetic energy it has. • Kinetic energy depends on both mass and velocity.

29. Forms of Energy • The six main forms of energy are: • Electric • Heat • Chemical • Electromagnetic (light) • Nuclear • Mechanical • Other (gravitational, spring, magnetic)

30. Energy Jigsaw Assignment • Group any types, sources, or associated words that seem to refer to the same type of energy. • You can do this using colored pencils, or by making lists of each set of words that seem to be a given type of energy. • Try to get all of the words into 7 categories, one for each basic type of energy.

31. Electrical (PE) • flow of mobile electrons • A bolt of lightning contains enough energy to toast 160,000 pieces of bread. Unfortunately the bolt only takes 1/10,000 of a second – so turning the bread over might prove difficult.

32. Heat / Thermal Energy (KE) • The internal motion of the atoms is called heat energy, because moving particles produce heat • Heat energy can be produced by friction. • Heat energy causes changes in temperature and phase of any form of matter. • heat as energy

33. Chemical Energy (PE) • Chemical Energy is required to bond atoms together. • And when bonds are broken, energy is released.

34. Chemical Energy • Fuel and food are forms of stored chemical energy. • One kilogram of butter stores as much energy between its atoms as the same quantity of TNT.

35. Frequencies of radiation in the electromagnetic spectrum—waves are always in motion

36. Electromagnetic Energy (KE) • Light is a form of electromagnetic energy. • Each color of light (Roy G Bv) represents a different amount of electromagnetic energy. • Electromagnetic Energy is also carried by X-rays, radio waves, and laser light.

37. Did you know? • If 10 kilograms of matter spontaneously turned into energy there would be enough energy to power a 100 Watt light bulb for 300 million years!!!

38. Nuclear Energy (PE) • The nucleus of an atom is the source of nuclear energy.

39. Nuclear Energy • When the nucleus splits (fission), nuclear energy is released in the form of heat energy and light energy. • Nuclear energy is also released when nuclei collide at high speeds and join (fusion).

40. Nuclear Energy The sun’s energy is produced from a nuclear fusion reaction in which hydrogen nuclei fuse to form helium nuclei.

41. Nuclear Energy • Nuclear energy is the most concentrated form of energy. • The amount of sunlight reaching the earth's surface is 6,000 times the amount of energy used by all human beings worldwide. The total amount of fossil fuel used by humans since the start of civilization is equivalent to less than 30 days of sunshine.

42. Mechanical Energy (KE) • The motion of objects • Kicking a football • Throwing a bowling ball

43. Check 4 Understanding • Energy of stars • Energy of a substance changing states (gas to liquid, liquid to solid, etc) • Energy of batteries • Energy of tanning lamps • Clicking of a computer mouse • Energy of lightning • Nuclear fusion • Heat • Chemical • Light (ultraviolet) • Mechanical • Electrical

45. Warm Up • Classify these forms of energy as Kinetic or Potential energy • Electric • Heat • Chemical • Electromagnetic (light) • Nuclear • Mechanical

46. September 14, 2010 Agenda • The Law of Conservation of Energy • Energy Conversions Homework Begin Research Unit 3 Worksheet 1

47. Law of Conservation of Energy Energy cannot be created or destroyed but it can change its form. Compound Machines Energy IN = Energy OUT Energy released = Energy absorbed Energy of a system = Energy of surroundings

48. The Law of Conservation of Energy • Energy can be neither created nor destroyed by ordinary means. • It can only be converted from one form to another. • If energy seems to disappear, then scientists look for it – leading to many important discoveries.

49. System: whatever we’re studying • Surroundings: everything outside the system • Universe = system + surroundings • If we’re studying a space heater, the heater will be our system, the house will be our surroundings, and the universe will be the heater and the house together (we ignore the irrelevant rest of the world, since it doesn’t really play a part in anything).

50. Energy Conversion • Energy can be changed from one form to another. Changes in the form of energy are called energy conversions.