Environmental Engineering Reference
In-Depth Information
cuts through the magnetic field, resulting in a
flow of electrons through the wire. (Moving elec-
trical charges possess both an electric and a
magnetic field.) This process generates an al-
ternating current that passes into electrical
transmission lines. This is the form of electrical
energy we use in our houses. Anything that
turns the copper coil through the magnetic field
possesses kinetic energy that can create elec-
tromagnetic energy, including wind or water
turning a turbine, or coal or nuclear fusion boil-
ing water, whose steam powers similar turbines.
Nuclear energy
is stored in the nuclei (core) of an atom
and is released when an atom splits apart or two atoms join
together. The process of splitting an atom is called
fission,
and the process of joining atoms is called
fusion.
For ex-
ample, fission occurs in nuclear power plants when huge
amounts of heat are created by splitting the nuclei of urani-
um atoms. The process of fusion occurs when the sun com-
bines the nuclei of hydrogen atoms.
Gravitational energy
is energy stored in an object's height.
The higher and heavier the object, the more gravitational
energy is stored. When you ride a bicycle down a steep hill
and pick up speed, your gravitational energy is converted to
motion, or kinetic energy. Hydropower generation converts
the gravitational energy of water in reservoirs to kinetic en-
ergy of moving water, which drives turbines that create elec-
tricity.
Electrical energy
is created from the motion of electrons.
Electrical energy is transferred by tiny charged particles
called
electrons,
typically moving through a wire. Just as
gravitational energy is stored in stationary water in reser-
voirs, electrical energy is stored in batteries. When electrical
energy is allowed to convert itself into the kinetic energy of
electrical current, it can be used to power a cellphone or
start a car. During a storm, electrical energy may be gener-
ated and released as lightning. Walk across the carpet on a
dry day and you store electrical energy in your body, which
you release with a small zap when you touch a conductive
object. This is static electricity.
The following table contains some of the most common energy terms used in AP Environmental Science.
Common Terms Used in AP Environmental Science
Term
Definition
British
Thermal
Unit (BTU
or Btu)
The amount of heat it takes to raise the temperature of 1 pound of water by 1°F
