Energy is the capacity to work. It may exist in many forms.
Sun gives its energy in the form of heat and light. Cars are
energized by gasoline, a type of chemical stored energy.
Food stored energy enable us to walk around and play. Energy
can be found in mechanical, thermal, chemical, electrical,
radial (light) and nuclear forms.
Mechanical energy is divided to:
Stored energy (Potential energy)
Moving energy (kinetic energy)
A lifted object to a certain height stores energy in a
potential form. When we leave its holding, it consumes its
energy in a moving (kinetic) form. As it is obvious, higher
lifts result of further falls.
Thermal energy is measured in English unit BTU.
One BTU is the amount of energy to raise on Pound of water
to one degree Fahrenheit it higher.
One average candy bar contains about one thousand BTU.
Energy can change its form but there is no creation or
destroying form of energy. Energy must be remained in one of
For instance, chemical energy of a battery transformed to
electrical energy which then can be changed to light energy
in a flashlight.
Heat energy is transferred in three forms: