The Principles
of Heat, Light,
and Sound
Heat
The movement of
heat is from…
Hot
Cold
Heat is transferred
three ways…
Conduction
Convection
Radiation
The first form of
heat transfer is…
Conduction
Conduction is heat
transferred by contact.
Source: Maybryonline.org
Examples…
University of Virginia Physics Department
Mr. Hand's 8th Grade Science Site
What stops heat
transfer?
An Insulator.
Examples…
The second form
of heat transfer is…
Convection
Hot rises, cold falls
creating currents.
“Older Than Dirt” WebQuest
Think Energy (UK)
Examples of
convection
The third form of
heat transfer is…
Radiation
Radiation is heat as
an electromagnetic
wave.
The wave becomes
heat when it hits an
object.
Examples of
radiation
Light
Sources of light…
A light source
produces light.
What happens when light
hits an object?
The light is reflected off
the object.
We see things because of
reflected light.
We see red, because red
light is reflected; blue
because blue is reflected;
white because all light is
reflected.
We see ourselves in a mirror
because of reflection.
The light that hits an object is
called the angle of incidence.
The light that bounces off the
object is called the angle of
reflection.
Angle of incidence =
Angle of reflection
Molecular Expressions
When light passes thru
transparent objects (water,
glass, etc.), the light is
refracted (bent).
When light passes thru
water, it’s refracted.
http://www.nature.com
When light travels thru a
prism, the refraction forms
the spectrum.
DiscoveryEducation Clipart
The spectrum is the colors
of the rainbow…
DiscoveryEducation Clipart
Red, Orange, Yellow,
Green, Blue, Indigo, and
Violet (ROY G. BIV).
DiscoveryEducation Clipart
Three things can happen
when light hits an object.
If the object is transparent,
it will pass through it.
If the object is translucent,
light is diffused as it passes
through it.
Designbuild-Network.com
If the object is opaque, the
light will not pass thru the
object and is reflected.
Sound
Sound is caused
by vibrations.
Sound moves out
in every direction.
To have sound,
you must have a
medium.
If there is no medium,
there is no sound.
A property of
sound is pitch.
Pitch is how high
or low a sound is.
How much energy
is used determines
the volume (how
loud) of the sound.
A lot of energy –
a loud sound.
A little energy – a
soft sound.