Conservation of Energy and Energy Resources Chapter 9

Friction and Energy When is converted, some of that energy might be changed in a different way due to friction. When a roller coaster goes down a hill, energy becomes energy. But some energy is also changed to energy (heat) from the friction of the wheels on the track. energy potential kinetic thermal

The Law of Conservation of Energy This law states that energy cannot be or. It can only be changed from one form to another. The total amount of energy in a closed system always stays the same. For instance, light energy is changed to chemical energy in an apple, but the amount of energy stays the same. createddestroyed

Perpetual Motion It is impossible to design a machine that puts out exactly the same amount of energy as it takes in, because some energy is converted to energy due to. A machine such as this would be 100% efficient. thermal friction

Energy Efficient If a machine is, it means that the amount of before a conversion is close to the amount of useful energy after the. An example would be an energy efficient car. A car with high energy efficiency can go farther than other cars with the same amount of gas. energy efficient energy conversion Do you have an energy efficient car?

Nonrenewable Resources Nonrenewable resources are energy sources that be replaced or are replaced much more slowly than we are using them up. like oil and natural gas are nonrenewable resources. cannot Fossil fuels

What fossil fuel do we use the most?

Fossil Fuels Fossil fuels like, coal, natural gas are formed from the buried remains of and animals that lived long ago. They are concentrated forms of the sun’s energy. The energy is when we burn them. oil plants released

Electric Generators Electric convert the chemical energy in fossil fuels into energy that we use in our homes and schools. This is the main source of electrical energy in the United States today. generators electrical

Nuclear Energy Another way to generate electricity is to use nuclear energy. Nuclear energy is generated from radioactive elements such as uranium. The supply of uranium is limited, so nuclear energy is a nonrenewable resource, like oil and coal.

Renewable Resources Some forms of energy can be replaced more quickly than they are used. These are known as. Some examples of renewable resources are energy, wind energy, from water, biomass, and geothermal. renewable resources solar energy

Solar Energy: Energy from changed in solar cells. Energy from water: Energy that is gained from falling Wind Energy: Energy that is gathered from air. Geothermal Energy: Caused by the of Earth’s crust. Biomass Energy: Caused by the burning of, wood, and waste matter. sunlight water (dams). moving heating plant

Advantages and Disadvantages There are many advantages and disadvantages to the different forms of renewable resources. For example, geothermal energy can only be obtained from certain “hot spots” on Earth. Can you think of a disadvantage to each form of energy? (biomass, wind, solar, water energy)

Quickie Quiz 1.When a roller coaster car is at the top of a hill, ready to go down, it has: a.Kinetic energy b.Mechanical energy c.Potential energy d.Elastic potential energy

Quickie Quiz 2. If you have a car that drives a long way on a small amount of fuel, it is because: a.Your car has friction. b.Your car has potential energy. c.Your car is energy efficient. d.Your car converted electrical energy to chemical energy.

Quickie Quiz 3. The Law of Conservation of Energy states that: a.Energy cannot be created or destroyed. b.Energy cannot be converted. c.Energy can be created or destroyed. d.Energy in a closed system changes all the time.

Quickie Quiz 4. Which of the following is NOT a renewable resource? a.Wind energy b.Coal energy c.Solar energy d.Biomass energy

Quickie Quiz 5. Which type of energy is a nonrenewable resource? a.Solar b.Geothermal c.Natural gas d.Water

Quickie Quiz 6. Which form of energy is inexpensive and renewable, but requires large amounts of farmland and produces smoke? a.Geothermal b.Wind c.Water d.Biomass

Quickie Quiz 7. Which form of energy does not produce pollution, but produce radioactive waste? a.Solar b.Biomass c.Nuclear d.Wind

What do you think? Which form of energy do YOU feel we should most explore for future energy use? Why?