Download ENERGY is…

ENERGY is…
the ability to do WORK or cause change
Name 2 things that ARE energy or that HAVE energy
WORK is…
when a FORCE moves an object
a FORCE is… a push or a pull
There are two main kinds of energy…
POTENTIAL ENERGY
STORED energy
or
Energy that is NOT being used
Examples:
KINETIC ENERGY
Energy in MOTION
or
Energy that IS being used
Examples:
Write a “P” or a “K” under each picture
on your paper to tell whether the pictures
are showing POTENTIAL or KINETIC
energy.
zzzz
K
P
K
K
P
DIFFERENT FORMS OF ENERGY
Both potential & kinetic energy come in many
forms. Six of the most common ones are:
Sound Energy
Energy of virbrating particles
THERMAL (HEAT) ENERGY
Energy of the heat IN an object
CHEMICAL ENERGY
Energy in chemical bonds of
food, gas, batteries, burning
wood etc.
DIFFERENT FORMS OF ENERGY (continued)
ELECTRICAL ENERGY
Moving electrical charges
ELECTROMAGNETIC ENERGY
(light/radiant)
Light energy, X-rays, radio waves
NUCLEAR ENERGY
Stored in the nucleus of an
atom & released when atoms
are split or joined together,
nuclear reactors, atomic
bombs, stars, sun
 Sound
energy is the energy
produced by sound
vibrations as they travel
through air, water, or any
other space. This type of
energy is a form
of mechanical energy. Most
people and animals can
register this sort of energy
with their ears and it’s fairly
easy to identify.
SOUND ENERGY
 Thermal
energy is the
energy that comes
from heat. This heat is
generated by the
movement of tiny
particles within an
object. The faster these
particles move, the
more heat is
generated. Stoves and
matches are examples
of objects that
conduct thermal
energy.
THERMAL ENERGY
 The
energy that results
during a chemical
reaction is called chemical
energy. It is a type of
potential energy.
Chemical energy is stored
within the bonds of the
atoms and molecules that
make up a substance.
Once chemical energy is
released from a
substance, the substance
is transformed into a new
substance.
CHEMICAL ENERGY
 Electrical
energy is
energy that is caused
by moving electric
charges. Since the
electric charges are
moving, this is a form
of kinetic energy. The
faster the electric
charges are moving
the more electrical
energy they carry.
ELECTRICAL ENERGY
 The
potential for light
to perform work is
called light energy.
Light energy is the only
form of energy that we
can actually see
directly. Light energy
can also be converted
into other forms of
energy.
ELECTROMAGNETIC (LIGHT)
ENERGY
 1.The
energy released b
y a nuclear reaction, es
pecially by fission or fusi
on.
 2.
Nuclear energy regar
ded as a source of pow
er. Also called atomic e
nergy.
NUCLEAR ENERGY
ENERGY CONVERSIONS
(ENERGY TRANSFORMATIONS)
Energy can be converted (transformed or changed)
from one form to another.
For example…
1) Food has POTENTIAL CHEMICAL energy.
2) When you eat it, the bonds in the atoms are broken
and the energy is released to your cells.
3) Your body CHANGES the chemical energy to KINETIC
MECHANICAL ENERGY when you run, jump, write, walk.
4) Finally, your body creates THERMAL (HEAT) ENERGY you
can feel because the molecules inside you are moving!
Think about the energy conversions taking
place with a flashlight.
Use the flow chart in your notes to
show each form of energy that occurs.
Batteries
CHEMICAL
ENERGY
Wires
ELECTRICAL
ENERGY
Lightbulb
ELECTROMAGNETIC
(Light)ENERGY
Label the ENERGY CONVERSIONS in your notes.
ELECTRIC PENCIL SHARPENER
WIRES
electrical energy
GEARS & BLADES
mechanical energy
HEATING PAD
WIRES
electrical energy
HEAT
thermal energy
PLANT
SUN
PHOTOSYNTHESIS
Plant changes sunlight and water
into sugar (food) for plant!
electromagnetic
(light)energy
chemical
energy
CONSERVATION OF ENERGY
P.E  K.E.  P.E.  K.E. … Is energy lost?
No! Energy is converted!
Law of Conservation
The law of conservation of energy states that
when one form of energy is converted to
another, no energy is destroyed in the
process.
Energy cannot be created or destroyed, so the
total amount of energy is the same before and
after any process. All energy is accounted
for.
Conserving Energy
When you hear or read about conserving energy,
don’t get confused with the law of conservation of
energy. Conserving energy means saving energy, or
not wasting it!
In Science, energy is always conserved because its
total quantity does not change.
LAW OF CONSERVATION OF ENERGY

Energy can be neither created nor destroyed.

The total energy in a “closed” system is always the same.

The energy may be in different forms, but the amount will
be equal.
Energy Conversion in a Waterfall
The water at the top of the falls has
gravitational potential energy because it is
higher than at the bottom. As the water
falls, its height decreases, and loses its
potential energy. At the same time, its
kinetic energy increases because its
velocity (speed) increases. The potential
energy is converted into kinetic energy.
Gravitational
Potential
Energy
Kinetic
Energy
QuickTime™ and a
TIFF (U ncompres sed) decompressor
are needed to see this picture.
CONSERVATION OF ENERGY

Thermal Energy produced by friction is not useful energyWhy?

It IS NOT used to do work.
PERPETUAL MOTION

A machine that would run forever without the addition of
energy.

Some energy is wasted due to the thermal energy
produced, so perpetual motion is not possible.

So How does the “drinking bird” work?