2. ENERGY Energy is defined as the ability to do work or cause change. **Work is done when a force moves an object through a distance.

3. POTENTIAL and KINETIC Two TYPES of Energy…

4. POTENTIAL Energy  Potential energy is energy that is STORED in an object.  Energy can be stored due to the position of the object or chemically. Examples include: Batteries Water behind a dam A rock at the top of a hill Oil and coal Food

5. EXAMPLES of Potential Energy

6. KINETIC Energy KINETIC  Is the energy of motion.  The amount of kinetic energy an object has depends on it’s mass and speed. Examples include: A moving car Water falling over a dam Windmill turning A child running A ball rolling down a ramp

7. Examples of Kinetic Energy

8. BACK AND FORTH Energy can switch back and forth between potential and kinetic. Think of a roller coaster. A chain pulls the cart up to the top of the first hill ( Kinetic to potential). The coaster has maximum potential at the top. As the train falls down the hill the potential turns to kinetic with full kinetic at the bottom, and begins again.

9. KINETIC ENERGY Kinetic energy is motion––of waves, electrons, atoms, molecules, substances, and objects. POTENTIAL ENERGY Potential energy is stored energy and the energy of position––gravitational energy. There are several forms of potential energy.

11. FORMS OF ENERGY (Different ways that objects can possess energy) Mechanical (Moving, includes sound) Chemical Thermal (Heat) Electrical Electromagnetic (Radiant) Nuclear

12. Energy of movement, like kinetic energy. Examples: Walking, a car moving, a ball being kicked or hit with a bat. MECHANICAL

13. CHEMICAL Energy stored in chemical bonds of compounds. This energy is released when we break up the compound (chemical changes). Examples include when we burn oil or digest food.

14. THERMAL (HEAT) Energy given off as heat. The amount of heat energy an object has is measured in degrees of temperature.

15. ELECTRICAL Energy created by the flow of electrons from one atom to another. The moving electrons are called “current”

16. ELECTROMAGNETIC (Radiant) Electromagnetic energy is energy that travels in waves. The sun’s energy travels to use as electromagnetic waves. The energy is carried in small packages called photons.

17. NUCLEAR Nuclear energy involves changes in the nucleus of atoms. Nuclear energy powers the sun and occurs on earth in the atoms of radioactive elements mostly in the core of the earth.

18. MORE CHANGE Energy has the ability to changes forms. Chemical energy of food becomes mechanical energy of moving muscles. Mechanical energy of moving wind can be changed by a turbine into electrical energy.

19. Earth’s Energy Sources Our earth system has 2 sources of energy. 1)The major source of energy for life on earth is the sun with it’s giant nuclear furnace. 2)On a much smaller scale is the geothermal heat from inside the earth.

20. SOLAR ENERGY/ SOLAR RADIATION The sun is a giant nuclear furnace that sends out a constant stream of energy in the form of heat and light. Solar radiation is classified into groups based on wave length. *When energy is transferred by waves the heat transfer is called radiation.

21. Solar Radiation Electromagnetic Spectrum There are seven categories of solar radiation. The categories are based on wavelength. Wavelength: The distance between two wave crests

22. Kinds of Radiant/Electromagnetic Energy 1)Radio: Longest wavelength, least energy 2)Microwaves 3)Infrared Rays 4)Visible Light: The only waves in the spectrum we can see 5)Ultraviolet 6)X-Rays 7)Gamma Rays: Shortest wavelength, most energy

25. Visible Light Located in the middle of the spectrum. It is the only part of the spectrum we can see. Red has the longest wavelength Violet has the shortest

27. How does solar energy affect us? Trapped by the atmosphere and warms the earth Heats up the ground which heats up the air. Hot air rises and forms wind and weather. Heats up the ocean water and causes motions such as currents. Light from the sun is used by plants for food. This food feeds us.

28. Greenhouse Effect 1. Earth has a layer of gases that surrounds it called the ___________________________. 2. This layer acts like glass in a car or building and lets _________________ in. Some of the heat leaves but some is _____________________ and this keeps the earth warm at night. 3. Certain gases hold __________ heat than others. These ___________________ _____________ are slowly making the earth ____________________.

30. GEOTHERMAL energy Geothermal energy is the heat from the Earth. It's clean and sustainable. Geothermal energy ranges from the shallow ground to hot water and hot rock found a few miles beneath the Earth's surface, and down even deeper to the extremely high temperatures of molten rock called magma. Naturally occurring large areas of hydrothermal resources are called geothermal reservoirs. Most geothermal reservoirs are deep underground with no visible clues showing above ground. But geothermal energy sometimes finds its way to the surface in the form of: Volcanoes and fumaroles (holes where volcanic gases are released) Hot springs Geysers Most of the geothermal resources in the United States are found in the West:

31. HUMANS USE LOTS OF ENERGY Our society is dependent on having free flowing sources of energy. Where do we get all of this energy? How do we classify our energy sources?

32. What do we use energy for? Food_____________ Heat our homes_____________ ___________________________

33. We classify our energy sources into two groups Renewable Non-Renewable

34. RENEWABLE ENERGY SOURCES… Are sources of energy that are constantly being produced or can be grown or made within 20 years (short period of time). Examples include SolarBiomass WindHydro (moving water) Geothermal

35. Advantages of renewable energy sources Energy created through renewable means can help our environment in several ways: Saves burning fossil fuels Creates less pollution May have a constant supply Does not emit greenhouse gases.

36. GEOTHERMAL Thermal energy that comes from inside the earth. Radioactive elements deep in the core of the earth produce heat that warms rock and water. We can use the steam and hot water produced inside the earth to heat buildings or generate electricity Warm water is often used as a source of heat for homes.

37. Geothermal Energy… Geothermal energy is generated in the earth's core, about 4,000 miles below the surface. Temperatures hotter than the sun's surface are continuously produced inside the earth by the slow decay of radioactive particles, a process that happens in all rocks.

38. WIND Wind is caused by the uneven heating (land vs. water) of the earth’s surface by radiant energy from the sun. The ground warms the air above it and causes wind. We can use wind turbines to get electricity. As long as the sun shines the wind will blow!

39. SOLAR ENERGY We use both forms of energy from the sun: –Heat (radiant) which is transferred in waves (radiation). –Visible light We use the sun’s energy to heat buildings & water and to generate electricity.

40. Solar Energy: RADIATION Heat from the sun is absorbed by dark surfaces and is used to heat water in solar heaters. This heat transfer in waves is called radiation heat transfer. Solar heaters on roof tops work this way

41. Solar Energy: Light Visible light from the sun is transformed into electrical energy in solar cells. Calculators and large solar cells in the desert are examples.

42. HYDROELECTRIC The mechanical energy of moving water is changed into electricity. Sources of moving water include rivers, dams, and in some places the tides.

43. Biomass Is any organic matter (anything that was once alive) that can be used as an energy source. Biomass gets its energy from the sun. Ex: wood, crops, wastes.

44. Disadvantages of renewable fuel sources Not available in all areas: (some areas do not have wind, or tides or places to grow trees.) Not all machines are designed to use these types of fuel sources. Can be more expensive

45. Why don’t we use more Renewable energy sources? In the past, renewable energy has generally been more expensive to use than fossil fuels. Plus, renewable resources are often located remote areas and it is expensive to build power lines to the cities where they are needed. The use of renewable sources is also limited by the fact that they are not always available (for example, cloudy days reduce solar energy, calm days mean no wind blows to drive wind turbines, droughts reduce water availability to produce hydroelectricity).

46. NON-RENEWABLE Fuel resources that are not replaceable within 100 years. Most nonrenewable fuels are FOSSIL FUELS Coal Oil ( petroleum) Natural Gas *Nuclear Fuel is considered Non-renewable*

48. What is a fossil fuel? Fossil fuels are the remains of ancient organisms changed by time, heat and pressure. Fossil fuels are rich in the elements hydrogen and carbon. Energy from the sun is stored in fossil fuels as chemical potential energy.

49. How we got fossil fuels

50. EXAMPLES OF FOSSIL FUELS OIL (PETROLEUM) COAL NATURAL GAS

51. Uses of Fossil Fuels 1)Industry: Used to make fabric and run machines 2)Transportation: Gasoline is made from Petroleum 3)To produce electricity

52. Disadvantages of Fossil Fuels They pollute the atmosphere They will not always be available because we are using them up.

53. Why do we still use Nonrenewable fuels? They are still relatively inexpensive. They produce a lot of power. Most of our machines are designed to run on gas or oil from fossil fuels.