WORK Potential Kinetic

Transcription

1 Energy

2 What is energy? - Ability to do WORK - The transfer of energy is work, power is the rate at which energy is transferred. - There are many forms of energy (chemical, mechanical, nuclear, thermal, etc ), but all can be put into two categories: Potential & Kinetic

3 Potential Energy Stored energy - It has the potential for energy 1. Chemical Energy 2. Elastic Energy 3. Nuclear Energy 4. Gravitational Energy 5. Electrical Energy.

4 Kinetic Energy Energy in Motion 1. Radiant Energy 2. Thermal Energy 3. Mechanical Energy 4. Sound Energy

5 Turbines Basically a fan that when turned generates an electrical current that we can use as electricity. Anyway that we can turn a turbine will give us electricity. Most common way is to heat water, which produces steam that spins the turbine.

6 What do we do with all of this energy!? Anything we can think up! but we have to have potential energy to get kinetic energy.

7 Where do we get potential energy? Currently, almost 75% of our energy needs comes from fossil fuels.

8 Renewable Energy Sources Geothermal Wind Tidal Hydroelectric Biomass Solar

9 Solar The sun constantly gives off energy in the form of light and heat. The earth receives enough energy from the sun each day to power the earth for 40 years! Solar rays are collected by a photovoltaic panel and which use them to create an electrical current Major drawbacks of solar energy are: the large area required to collect it can only collect on sunny days

10 Geothermal We drill into the crust and allow the intense heat from the Earth s interior to escape, either as steam or hot water and use it to turn a turbine. Does not pollute the air

11 Geothermal Heating & Cooling of homes or businesses

12 Geothermal Unit inside the house About the same size of a normal heat and air unit.

13 Wind Wind is air in motion. Wind turns the turbine. Has been harnessed for power for many years (back to the Egyptians). American colonists used windmills to grind wheat and corn, pump water, and cut wood. Fastest growing energy source in the world. Few environmental side effects.

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15 Hydroelectric Currently the most common form of alternative energy (Beaver Dam). Hydropower is the ideal fuel for electricity because there are no waste products, but dams create other environmental problems.

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18 Tidal Energy takes advantage of the cycles of the moon and the motion of the sea power is generated as the tide comes in and goes out by turning a turbine.

19 Biomass Organic material made from plants and animals. When burned releases heat (& CO 2 ). Come from a wide variety of sources.

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21 Fossil Fuels Fossil fuels are potential energy Energy rich substance formed from the remains of once living organisms Major Types Coal Oil Natural gas Read pages

22 Coal Formed from the remains of once living organisms under a long period of high pressure and temperature. Most abundant fossil fuel - cheap Used to generate more than 1/2 of all electricity. Disadvantages: When burned it produces carbon dioxide, sulfur, and mercury that result in global warming, acid rain, and mercury poisoning. Dangerous to mine. Nonrenewable

23 Oil (Petroleum) Yellow to black, thick liquid found underground Formed from the remains of once living organisms in an oceanic environment under a long period of high pressure and temperature. Crude oil (oil fresh out of the ground) is sent to a refinery where they separate it into different kinds of fuels. Disadvantages: 1. Produces CO 2 when burned that contributes to global warming 2. More expensive to mine than coal and not found everywhere.

24 Natural Gas Because natural gas is colorless, odorless and tasteless, mercaptan is added to serves as a safety device (it smells like rotten eggs). Natural gas burns more cleanly, however, it does still produce CO 2 which can lead to global warming. It can be condensed to a liquid making it easy to transport. Disadvantages: 1. Produces CO 2 when burned that contributes to global warming 2. It is highly flammable and toxic to breathe for a long period of time.

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26 Nuclear Power Accounts for about 20 percent of electricity generated in the US. The heat produced comes from the fission or splitting of uranium atoms. Nuclear electricity does not produce carbon dioxide. Radioactive wastes cause concern for nuclear power.

27 Nuclear Power Plant Read pgs