Sound and Light Study Guide (SOL 5.2 & 5.3)

Cooperative Learning
Read through this study guide.  When you are finished, work with a partner from your group and
ask your partner to quiz you on the questions.  When you know most of the answers, trade.

What two characteristics of sound does a wave’s frequency show us?

Amplitude (loudness)
The amplitude is shown by the height of the frequency wave.

Pitch (how high or low the sound is)
The pitch is shown by how squished together the waves are.  If they are bunched tightly together,
the pitch is high, like the singer Mya’s voice.
If the waves are spread out, the pitch is low, like Christina Aguilera’s voice.

Sound, Morse Code, flashes of light, and sign language are all ways that people ___________.

Draw a frequency diagram with 3 wavelengths.

(You measure wavelength from trough to trough or from crest to crest on a frequency diagram.)

Does sound travel better through a liquid or a solid?  Why?
It travels better through a solid because a solid is denser.

How does a fisherman use sonar?
A fisherman uses sonar to locate fish.  The sonar device usually shows the depth and distance
of fish on a small computer screen so that fishermen can easily read it.

Sonar equipment uses sound waves to locate the location of things like fish.  If you ever go fishing,
you might see a sonar detector on a boat.  The sonar equipment sends sound waves into the water,
and when there are fish in the water, the sound waves bounce off of them and return to
the sonar detector more quickly than the sound waves that reach the bottom of the lake or
ocean and then bounce off.

What seven colors will you see in a rainbow?
Remember Roy G. Biv (red, orange, yellow, green, blue, indigo, violet)

What is happening when a pencil looks bent in a glass of water?
Refraction is occurring because water slows light waves down.

Is a pencil opaque, transparent, or translucent?

Is a window pane opaque, transparent, or translucent?

Is a glass of cherry Kool-aid opaque, transparent, or translucent?

Facts to know:
Sound is used as a means of communication.  When we speak, our vocal chords vibrate
and the sound waves are transmitted to our friends’ ears.  The friends hear our speech,
so we use speech to communicate.

Sound travels fastest through a solid.  Think about the time your experiment partner
scratched the wooden door in our classroom and you listened for the sound on the other side.
Solids transmit sound much better than gases do.

Water transmits sound better that gas does.

Morse code is one way to use sound to communicate over long distances.

The visible spectrum shows us seven distinct colors.  The visible spectrum can be seen when
there is a rainbow outside.  Also, you can hold a prism up and bend a beam of white light
so that it spreads out and you can see the visible spectrum of light.  The colors are red, orange,
yellow, green, blue, indigo, and violet.  Remember ROY G. BIV.

Light waves can be reflected.  You see this happen every time you look into a mirror.

Light waves can be refracted.  You see this when you put a pencil in a glass of water.
It looks like the pencil in bent because light waves travel more slowly in water.

Light waves travel about 186,000 miles per second in air.

Light waves travel 140,000 miles per second in water.

An object is opaque when NO light passes through it.  A pot is an opaque object.  If there
were a candle burning inside a metal pot, you would not be able to see the light through the side
of the pot.

An object is translucent when some light waves pass through it.  Think about looking through
a Tupperware bowl.  The image of your hand on the inside would be fuzzy.  Also, if you look through
colored glass, you are looking through a translucent object.

A transparent object is completely clear.  You see a nearly perfect image.  Think about looking out
the window.  You can see trees and buildings clearly.  The glass is transparent.  Remember the
difference between translucent and transparent by thinking about this:  Your parents can see right
through you (they know if you’re lying :) ) so the word transPARENT makes sense because it
describes things that you can see through perfectly.

A concave lenses curves IN.  It looks like it is caving in.  A convex lens curves outward, like a ball.