Transcript Forms of Energy

Forms of Energy
 Besides
potential and kinetic energy,
scientists also classify energy into
other forms such as: solar energy
which is either light or heat, chemical
energy, mechanical energy, electric
energy, sound energy, or thermal
energy.
 Solar
energy – energy that comes
from the sun as light or heat.
 Light
– radiation that we see.
(the flame of a candle that you see)
 Heat
– radiation that we feel.
(the flame of a candle that you see)

Energy from the sun travels as radiation.

The sun produces several kinds of radiation: light,
heat, and radio waves.

How does solar energy help us?

What would happen if we did not have solar
energy?
 Chemical
energy – energy that is
released through a chemical
reaction.
 When
it is not being used, chemical
energy is potential energy.
A
chemical reaction is needed to
change this potential energy into
kinetic energy.
 Many
substances release energy in
this way.
 Can
you think of some examples?

Burning is a chemical reaction that releases
energy.

If you set a burning candle under a dry twig,
what will happen?

If you set a burning candle under an iron bar,
what will happen?

What does this tell you about the chemical
energy stored in different materials?
 Mechanical
energy – the
combination of all the potential and
kinetic energy that something has.
 The
windup toy in the photo has a
key attached to a spring.
 When
you turn the key, you wind up,
or tighten, the spring.
 What
 What
kind of energy is this?
happens when the key is
released?
 What
 Does
is the toy’s kinetic energy?
the toy still have potential
energy as it is moving?
 Electric
energy – the energy that
comes from an electric current; also
known as electricity.
 Lay
your head down on your desk,
pretend you are at home and a
thunderstorm comes and knocks out
your power. You are now in a
blackout.
 What
electrical inconveniences do
you have?
 What
kind of energy does a handheld video game use for power?
 What
do you have to do to a handheld video gam in order for it to
work?
 What
kind of energy comes out of the
batteries?
 Sound
energy – energy in the form of
vibrations that travel through matter
 When
you speak, sound energy from
your voice meets air molecules and
starts them vibrating.
 They,
in turn, make molecules next to
them vibrate, and those make others
vibrate.
 That’s
why our voice can be heard
anywhere in the room.
 Suppose
I’m speaking loud enough to
be heard in the hallway, even though
the door is closed. What happens
when the air molecules next to the
door start vibrating?
 If
you place you hands on the radio
or television, you can feel the sound
vibrations.
 Some
people with hearing disabilities
have been able to become dancers
by feeling the vibrations of the music
through their feet.
 Thermal
energy – energy associated
with temperature; heat energy
 Remember
that all matter is made up of
tiny particles that are always moving.
 Since
they move, they have kinetic
energy; also known as thermal energy.
 The
faster the particles move, the more
thermal energy the matter has.
 Can
you give some examples of
thermal energy?
 Law
of conservation of energy –
energy can never be made or
destroyed, but it can change forms.
 Often,
one form of energy changes
into another form.
 The
batteries in a flashlight contain
chemical energy, but the flashlight
bulb gives off light. Where does the
light come from?
 The
batteries’ chemical energy
changes into electric energy.
 Then
the bulb in the flashlight
changes the electric energy into light
energy.