Transcript Energy Forms and Transformations

Energy Forms and
Transformations
Forms of Energy
Mechanical Energy
• Associated with the position and motion of an
object.
• A combination of an object’s PE and KE (total
energy of the object at any one time)
• An object with ME can do work on another
object.
• ME = the ability to do work
• The more ME, the more work an object can do
Calculating ME
• ME = PE + KE
• Sometimes an object’s ME is just its
potential energy and sometimes it is just
its kinetic energy.
At one point during the Super
Bowl, the football had a GPE of
32 J and a KE of 45 J. What
was the ball’s ME?
• ME = PE + KE
• ME = 32J + 45J
• ME = 77J
Other Forms of Energy
• Potential, Kinetic, and Mechanical are 3 types
of energy that deal with the motion and position
of an object.
• There are several other types of
energy that are associated with
the particles of objects.
Thermal Energy
• The particles that make up objects are called
atoms and molecules. They are always in
motion.
• The total kinetic and potential energy of the
molecules and atoms in an object is its
thermal energy.
Friction
• Friction turns mechanical energy into
thermal energy
• Energy “lost” due to friction still exists – it
is now the energy of heat!
Electrical Energy
• Electrical energy results from the
movement of charged particles.
• It can either be kinetic or potential
depending on whether the charges are
moving or stored.
Chemical Energy
• Everything is made of
chemical compounds
(which are made up of
atoms and molecules
bonded together).
• Chemical energy
comes from the bonds
of chemical
compounds. Breaking
and reforming those
bonds releases and
reorganizes energy.
• Example: Food!
Nuclear Energy
• Stored in the
nucleus (center) of
atoms… released
during a nuclear
reaction
• Nuclear Fission:
Splitting the nucleus
(Nuclear Power
Plants  electricity)
• Nuclear Fusion:
Nuclei join together
(Sun)
Electromagnetic Energy
• Travels in waves that have some electrical
properties and some magnetic properties
(hence the name!)
• All from the sun (although manmade machines
can produce them as well)
•
Examples:
microwave,
X-rays, radio
wave, sunlight
*Law of Conservation of Energy*
• Energy cannot be created or
destroyed
…but it can be transferred and
transformed!
• The total amount of energy
before any transformation is
equal to the total amount of
energy after
What’s the difference?
• Energy
Transformation:
Change from one
form of energy to
another form.
• Energy Transfer:
Energy goes from one
object to another as
the same form.
Transform/Transfer Pictures
Transfer kinetic
energy from player
to ball
Chemical energy of
food transformed to
kinetic energy of
boy
Transformations
• single
transformation :
• toaster
• electrical energy
to thermal
energy
Transformations
• multiple transformations: a match
• Striking match (mechanical) causes
friction (thermal) this releases the
chemical energy in the match which
creates fire (thermal and
electromagnetic (light))
A Common Energy Transformation
• Kinetic Energy to
Gravitational
Potential Energy
• When does this
happen?
– When a basketball
is tossed up
– When a person
jumps up and down
Gaining
GPE
Gaining
KE
Losing
KE
Losing
GPE