PhysicalScienceEnergy

This section will help a student understand that energy is found in many forms and that each of the forms is responsible for shaping our lives. Whithout energy, technological advancements, such as mortorized machines. Whithout energy, life itself would not be possible. The topics of potential energy, kenetic energy, and heat are used to develop the concepts of energy.

Energy Has Many Forms
Heat is the energy produced by moving atoms and molecules
Light energy travels in waves to reach your eyes
Chemical energy is the energy that binds atoms and molecules together.
Mechanical energy is the energy produced produced to move objects.

Energy is the ability to cause change and is the necessary ingredient for change. The amount of energy used to cause change is measured in joules (J)

To learn more about energy we have prepared a short movie for you to watch. When you are finished wathing the movie please return back to this page to answer some questions about what you have learned.

Stored Energy
The energy stored in an object due to its position is called potential energy. The energy stored in a rubber band is called elastic potential energy.

Another form of potential energy is gravitational potential energy. An example of gravitational potential energy is the energy an object has when it is in an elevated position. Anything that can fall or drop has gravitational potential energy.

Energy in Motion
The energy an object has due to its mass and its motion is called kinetic energy. Anything in motion has kinetic energy. The formula to measure kinetic energy is as follows:

KINETIC ENERGY = MASS X SPEED (Notice the equation uses speed instead of velocity.)
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Energy Laws
The First Law of Thermodynamics: The law of conservation energy states that the total amount of energy in the universe always stays the same. The law of conservation of energy is also called the first law of thermodynamics. Another way to say this is that energy cannot be created or destroyed. It can be changed from one form to another, but the total amount of energy never changes.

The Second Law of Thermodynamics: No machine is 100% efficient. The amount of work a machine does is always less than the amount of energy put into it. Whenever ther is an energy conservation, heat is produced that cannot be used to do useful work. The unuseable heat is called waste.

Perpetual Motion
Many people throughout history have tried to make perpetual motion machines. A perpetual motion machine is one that makes at least as much energy as it uses. In other words, a perpetual motion machine, once started, would continue operating forever with no loss of motion, no waste heat, no friction, and no additional energy input. No one has ever succeeded in making one of these machines because no one has yet found a way to get around the second law of thermodynamics. Even complex natural systems--such as the solar system--that appear to run without energy input have been found to be running down very slowly.

Energy and Life
Even living systems obey the second law of thermodynamics. Plants, animals, and all other creatures require a source of energy, such as food. Animals get food from eating plants or eat-ing other animals. Plants make their own food using sunlight, water, and carbon dioxide. Regardless of the type of living system and how it gets its energy, each produces heat and motion as a result of that energy.

Heat is Energy
As an object becomes hotter, its atoms and molecules move faster.
As an object becomes colder, its atoms and molecules move slower.
So you can say that heat is due to the motion of molecules or atoms. (The heat of an object is the total kinetic energy of the random motion of its atoms and molecules).
Many scientest have had questions about the relationship between work and heat.

To find out more on how heat is a form of energy watch the following movie

Heat and Temperature Compared
Teamperature is the measure of the average kinetic energy of the moving atoms and molecules of a substance.
Temperature measures how fast the average atom or molecule is vibrating while heat measures both how fast an atom or molecule vibrate and also how many molecules and atoms are vibrating.

To find out more about heat and temperature