TOPIC: Energy AIM: Describe the various sources of energy that exist on Earth. Do Now: y/formsofenergy/ y/formsofenergy/ HW: Work on your atom drawing/model. Due on Friday!!!!!

Which skier will have a greater potential energy? Support your answer.

Which of the following increases when a metal spring is stretched horizontally? 1.Potential energy 2.Kinetic energy 3.Gravitational potential energy 4.Electrical energy

Identify the form of energy being described. 1.Windmills 2.Food 3.Moving roller coaster 4.Created as a result of Friction 5.Gasoline 6.Created by light bulbs 7.A moving car 8.Batteries 9.Lightening 10.Found in the nucleus of an atom 11.Sunlight

A family is moving from Pennsylvania to Connecticut. As the moving van burns gasoline, it converts 1.chemical energy into mechanical energy 2.kinetic energy into potential energy 3.thermal energy into electrical energy 4.mechanical energy into kinetic energy

Which device produces mechanical energy? 1.A battery 2.A light bulb 3.An electric motor 4.A solar cooker

A song is playing on the radio. Which best describes the change in the flow of energy? 1.Electrical energy  light energy 2.Electrical energy  sound energy 3.Sound energy  light energy 4.Sound energy  electrical energy

Remember the Law of Conservation of Energy: Energy can’t be created nor destroyed, just changed from 1 form to another

Major source of Energy on earth The sun

Nonrenewable Energy Resources Resources that can’t be replaced by natural processes as quickly as they are used Takes millions of years for nature to reproduce

Examples of Nonrenewable Energy Resources 1.Fossil fuels = formed from remains of ancient plants & animals

Release carbon dioxide (global warming)

2.Petroleum: liquid, highly flammable Formed from plant remains

Used to produce: - Oil (burned to produce energy) - Lubricants (grease, motor oil)

- Plastics - Synthetic fibers - Asphalt

3.Natural Gas: Burned to provide energy for cooking, heating…

Burns more cleanly than other fossil fuels

4. Coal: solid fossil fuel

90% of coal used is burned to generate electricity

Creates more pollution

5. Nuclear Energy: found in the nuclei of atoms Power plants convert this to electrical energy

Use the process of FISSION (nucleus of atom breaks apart)

Advantages of nuclear energy Power plants could still produce electricity after coal and oil become scarce

Power plants need less fuel than ones which burn fossil fuels. (One ton of uranium produces more energy than is produced by several million tons of coal or several million barrels of oil)

Do not produce air pollutants & CO 2

Nuclear explosions produce radiation. –harms body cells  illness or death –Reactor disaster = meltdown. Fission reaction goes out of control  nuclear explosion Disadvantages of nuclear energy

Chernobyl, Ukraine, 1986 = reactor core overheated during safety test. Materials in the core caught fire and caused a chemical explosion that blew a hole into the reactor. Radiation was carried by the wind. Twenty-eight people died of radiation sickness.

Water used to cool power plants –excess heat may kill organisms in streams & rivers it’s released into

Wastes release radiation –Cannot be thrown away like garbage –Stored in special cooling pools at the nuclear reactors

TOPIC: Energy AIM: Describe the various sources of energy that exist on Earth. Do Now: Describe some examples of nonrenewable resources. HW: Work on your atom drawing/model. Due tomorrow!!!!!

Renewable Energy Resources Energy sources that can be replaced as quickly as it is used Will be around for millions of years

Examples of renewable Energy resources 1.Wind: windmills use wind energy to pump water –Connected to electric generator

No pollution Low costs But if there is no wind  no energy

2.Solar energy: more expensive than using fossil fuels

3. Moving water (Hydroelectricity): Electricity produced from energy of moving water

These use the GPE of water on hills to generate electricity as it flows downhill.

Tidal Power.

4. Geothermal energy: heat from earth’s interior (magma) Used to generate electricity

5. Biomass: renewable organic matter Example: wood, garbage, crops

Biogas is one of the most popular sources of renewable energy. It is derived from organic sources. Biogas generation is the process for producing biogas from organic matter. It is a good resource to make farms be independent as biogas can be used for electricity generation. Compressed biogas can also be used as an alternative vehicle fuel. It is a colorless, odorless, inflammable gas. It comprises of methane and carbon dioxide. Biogas is produced when organic matter is broken down by anaerobic bacteria. Bio energy is a major player in sustainable living in countries like India and China where individual biogas generators have been developed in villages to make them self-sufficient in terms of power generation.

Ethanol = clear, colorless alcohol fuel made from the sugars found in grains, such as corn & wheat, and potato skins & rice. It is renewable because it is made from plants. To make ethanol we use yeast to ferment the sugars and starch in corn. Corn is the main ingredient for ethanol in the US due to its abundance and low price. The starch is fermented into sugar  fermented into alcohol. Other crops such as, barley, wheat, rice, sorghum, sunflower, potatoes, sugar cane and sugar beets can also be used to produce ethanol.

Let’s summarize… 1.What is the earth’s main source of energy? 2.Describe nonrenewable resources and give some examples. 3.Describe some advantages and disadvantages of nuclear energy. 4.Describe renewable resources and give some examples.

Let’s summarize… 1.Explain the difference between renewable and nonrenewable resources.