Energy Conversion and Conservation

Conversions Between Forms of Energy

Energy Conversion: Is a change from one form of energy to another.

Most forms of energy can be converted into other forms.

Ex: Lamp and clock convert electrical energy into

electromagnetic. A water heater converts chemical energy in natural

gas to thermal energy.

Energy Conversions

Body converts chemical energy in the food you eat to mechanical energy you need to move your muscles. It is also changed into thermal energy your body needs to maintain its temperature.

A toaster converts electrical energy to thermal energy.

Series of Energy Conversions Strike a match:

Mechanical energy used to scratch the match is converted to thermal energy. The thermal energy causes the match to release stored chemical energy, which is converted to thermal energy and to energy you see as light.

Example of Series:

Car engine: Electrical energy produces a hot spark. The thermal energy of the spark releases chemical energy in the fuel. When the fuel burns, this chemical energy in turn becomes thermal energy. Thermal energy is converted to mechanical energy used to move the car, and to electrical energy that produces more sparks.

Law of Conservation

States that when one form of energy is converted to another, no energy is destroyed in the process.

Energy cannot be created or destroyed.

Conserving Energy

Means saving energy, or not wasting it.

This means that we should not waste fuels, such as gasoline, or our resources will be used up quickly.

Review

What is an energy conversion?

A change from one form of energy to another or an energy transformation.

Review - 2

State the law of conservation of energy in your own words.

The total energy before a process is the same as the total energy after.

Review - 3

Describe the energy conversions that occur when a ball is dropped and bounces back up. Why do you think the ball bounces a little lower each time?

As it falls, potential energy changes to kinetic energy. As it bounces back up, kinetic energy is converted to potential energy. The ball does not bounce a high because some energy escapes as thermal energy or sound when the ball hits the ground.

Formation of Fossil Fuel

Fuel: A material that stores chemical potential energy.

Fossil Fuels: Coal, petroleum, and natural gas.

Fossil fuels contain energy that came from the sun

Use of Fossil Fuel

Fossil fuels can be burned to release the potential energy stored millions of years ago.

Energy Conversions – Sun to Toaster

1) The sun converts nuclear energy to electromagnetic energy.

2) Ancient plants and animals convert electromagnetic energy from the sun to stored chemical energy.

3) Remains of plants and animals become coal over millions of years.

4) Stored chemical energy in coal is converted to thermal energy when the coal is burned to make steam.

5) Thermal energy is converted to mechanical energy as turbines are turned by steam.

6) Mechanical energy is converted to electrical energy as turbines turn electric generators.

7 Electrical energy is converted to thermal energy in your toaster