ENERGY AND ENERGY RESOURCES Calculating Power While energy is the ability to do work, and work is the transfer of energy, power is the rate at which work gets transferred. To calculate the amount of power used, use this formula: Power = energy transferred time Lesson Checkpoint: What is the difference between work and power? Kinds of Energy There are two kinds of energy: potential and kinetic. The energy of a moving object is called kinetic while the energy that is stored or exists because of the position of an object is called potential. The amount of kinetic energy an object has depends on its mass and velocity. An increase in either of these increases an object’s kinetic energy. The potential energy of an object due to gravity depends on the object’s height and weight. Once again, an increase in either of these increases an object’s potential energy. Lesson Checkpoint: What is the difference between potential and kinetic energy? Forms of Energy Energy can have many forms. Mechanical energy is the energy of a moving object such as an airplane in flight. Thermal energy or heat energy: When a sidewalk warms up from the sun it now has thermal energy. Electrical energy speaks for itself. Whenever electricity is used, its energy is being used. © Copyright NewPath Learning. All Rights Reserved. Permission is granted for the purchaser to print copies for non-commercial educational purposes only. Visit us at www.NewPathLearning.com.
Chemical energy is the energy that gets released when chemical bonds are broken. When a stick of dynamite blows up, the energy of the explosion is the result of the breakage of chemical bonds within the dynamite. Fossil fuels contain tremendous amounts of chemical energy. These fuels, including coal and natural gas, are called fossil fuels because they were formed in the earth millions of years ago. Right now, the burning of fossil fuels is the most common way we produce electricity. Nuclear energy is the energy within the nucleus of certain atoms. The energy that gets released in an atomic explosion is called nuclear energy. Electromagnetic energy is energy that travels in waves. Examples of this are microwaves, radio waves, and both infrared and ultraviolet radiation. Lesson Checkpoint: Name two forms of energy and give an example of each. © Copyright NewPath Learning. All Rights Reserved. Permission is granted for the purchaser to print copies for non-commercial educational purposes only. Visit us at www.NewPathLearning.com.
Changes in Energy’s Form When energy gets transformed from one form to another, this is called an energy transformation. There are many examples of this but one of the simplest is an electric toaster. Here, electricity is transformed into both thermal and electromagnetic forms: the electricity powers the waves of energy that heat the toast. When energy is transformed, no energy is either created or destroyed and this is referred to as the Law of Conservation of Energy. Lesson Checkpoint: Define energy transformation and give your own example of it. Alternative Energy Sources Since there is a limited amount of fossil fuel available on the earth, people are now turning to alternative sources such as wind power, solar power and atomic energy. • With wind power, wind is used to turn large windmills which turn generators to make electricity. • Solar panels can capture sun light and convert it to electricity right in their homes. • Atomic energy is another name for nuclear energy. In this case, large reactors break down radioactive atoms and release heat. This heat converts water to steam and this steam is then used to turn generators that make electricity. Lesson Checkpoint: Name an alternative source of energy that is used in your area and explain how it is used. © Copyright NewPath Learning. All Rights Reserved. Permission is granted for the purchaser to print copies for non-commercial educational purposes only. Visit us at www.NewPathLearning.com.