Section 2: Energy Can
change forms but is never
Energy is the ability to do work or to cause
Kinetic and Potential Energy are the main
There are several types of Energy, such
as Nuclear, Mechanical, Thermal,
Electromagnetic, Sound, and Chemical.
Energy often needs to be transformed in
order to produce a useful form of energy.
Conservation of Energy
The law of conservation of energy states
that energy is never created or destroyed.
No matter how energy is transferred or
transformed, it continues to exist in one
form or another.
Energy can be transformed in many different ways,
including from PE to KE and back again.
A measurement of
usable energy after
ratio of usable
energy to the total
energy after an
ENERGY STAR bulbs use 75
percent less energy than
bulbs and last up to 10
Produces 75 percent less
heat, so they're safer to
operate and cuts energy
costs associated with home
Unwanted forms of Energy
When energy changes
forms, the total amount
of energy does not
change, but some of the
energy may convert to
unusable or unwanted
Usually the unwanted form
Kinetic vs Potential
The picture on the left, because the child is at a higher
point above the ground.
Sun is the indirect source for almost all of Earth’s
energy, including plants, making sugars, as well as
fossil fuels that are burned for electrical energy or
a law that states that energy can never be
created or destroyed
energy simply changes form
The kinetic energy has been changed into sound, heat,
and then into kinetic energy in the second ball
Energy efficiency is a measure of usable energy after an
energy conversion. Energy-efficient appliances convert
a greater percentage of energy into the desired form.