Transcript ENERGY

ENERGY
FORMS OF ENERGY
S8P2. Students will be
familiar with the forms and
transformations of energy.
c. Compare and contrast the
different forms of energy (heat,
light, electricity, mechanical
motion, sound) and their
characteristics.
What is energy?
Energy
is the ability to
do work or cause
change.
Work is done when you
transfer energy to an
object and the object
moves.
What are the different
forms of energy?
Thermal
Energy
Chemical Energy
Electrical Energy
Electromagnetic Energy
Sound Energy
Nuclear Energy
What is thermal
energy?
Thermal
energy –
total amount of
energy in the
motion of the
particles contained
in matter.
Which picture has
greater thermal energy?
 BOX
2 – Same size boxes &
particles are moving with greater
speed in box 2
Which has more
thermal energy?
OR
Swan
sculpture – has
more mass - particles are moving
slower, but there are a
lot more of them.
How is heat related
to thermal energy?
Heat
is thermal
energy that is
transferred between
two objects of
different
temperatures.
What is chemical
energy?
Chemical
energy is the
energy that is stored in
chemical bonds.
(Atoms of elements that
make up compounds are
held together by
chemical bonds.)
What is electrical
energy?
Electrical
energy –
results from moving
charges.
–Ex. Computers, radios,
televisions, and lamps
(and other electrical
devices).
What is electromagnetic
energy?
Electromagnetic
energy
– energy that results
from the motion of
particles within atoms.
–Ex. X-rays, microwaves,
and ultraviolet (UV)
radiation
What is sound
energy?
Sound
energy is
given off by vibrating
objects.
Travels in the form
of waves.
What is
nuclear
energy?
Nuclear
energy is the
energy stored in the
nucleus of an atom as a
result from nuclear
forces.
–Ex: Fission and
Fusion
What is nuclear
fission?
Process
in which a
large nucleus of an
atom is split apart
to form two smaller
nuclei.
What is nuclear
fusion?
The
process in
which two small
nuclei are joined
together to form a
larger nucleus.
CONSERVATION OF
ENERGY
S8P2. Students will be familiar
with the forms and
transformations of energy.
a. Explain energy transformation in
terms of the Law of Conservation of
Energy.
b. Explain the relationship between
potential and kinetic energy.
What are 2 broad
classifications for
energy?
Kinetic
Potential
What is kinetic energy?
Energy
that results
from the motion of
an object.
What does kinetic energy
depend on?
MASS and VELOCITY
What is the formula
for kinetic energy?
KE = mv²
2
What is potential
energy?
Stored
Energy
Related to an object’s
position or composition
–Rock on a cliff has PE
due to its position
What does potential
energy depend on?
Mass & Height
What is the formula
for potential energy?
PE = m
x h
Potential
or
Kinetic?
What is the
law of
conservation
of energy?
While
energy may
change from one form
to another, energy is
neither created nor
destroyed.
What is mechanical
energy?
The sum of kinetic
and potential energy.
Stays constant within
a situation.
How is energy conserved?
Cart
has potential energy at
the top of the hill.
Once cart begins to move
potential energy decreases
and transforms into kinetic
energy.
Kinetic energy is the greatest
at the bottom of the hill.
Where are KE and PE
the greatest in this
diagram?
How can energy be
transferred?
 Energy
can be
transferred from
one form to
another.
 Turn on a lamp - electrical energy
transferred to light
and thermal energy
Plants convert electromagnetic
(light) energy from sunlight to
chemical energy through
photosynthesis.
 Your
body
converts stored
chemical energy
from food into
thermal energy
and kinetic energy
to make your body
maintain body
temperature and
to move.
HEAT TRANSFER
 S8P2.
Students will be familiar
with the forms and
transformations of energy.
–d. Describe how heat can be
transferred through matter by the
collisions of atoms (conduction) or
through space (radiation). In a
liquid or gas, currents will facilitate
the transfer of heat (convection).
What is does
temperature measure?
The
average
kinetic
energy of
the
particles in
motion.
Same temperature – different
thermal energy b/c more
mass in big pot.
How is thermal energy
transferred from one
object to another?
Heat
What is heat?
Transfer
of thermal
energy from higher
temperatures to lower.
Can be transferred
through matter in all
three phases.
How can heat be
transferred?
Conduction
Convection
Radiation
What is conduction?
Heat
transferred by
direct contact.
Transferred through
solids or liquids.
What is convection?
Heat
is transferred in
fluids (liquids or gases).
Transferred in fluids by
the movement of
currents that form in
fluids (convection
currents).
What is radiation?
Unlike
conduction and
convection, radiation
doesn’t require matter.
Heat is transferred by
electromagnetic waves.
We receive heat from the
sun through radiation.
Electromagnetic Waves
Heat Transfer
Illustrate where the transfer of heat
is taking place.