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Experiment: Sound
Use Andrew Lost: In the Whale
and these experiments to tune in to Andrew, Judy, and Thudd’s
frequency to appreciate of the spectacular properties of sound.
Materials: Heavy duty garbage bag, elastic
bands (thick), scissors, one box of cream of wheat or cream
of rice cereal
For each group: a pint or a quart plastic
containers or a margarine container, one large cooking pot
(two- or three-quart size), wooden spoon
Directions: (Advance preparation
for you to do) Use the plastic containers as templates.
Cut the plastic garbage bag into circles that extend 1 inch
beyond the open edge of the container. Cover each container
with one of the plastic circles and secure it with a thick,
tight rubber band. Pull the plastic as tight as possible.
(For students to do) Pour about a teaspoon
of cereal onto the plastic-covered container. Hold the cooking
pot with the open end facing the container, but not touching
it. Each student should bang on the pot with the wooden spoon.
Objective: Students can create the same
invention Andrew made with the Drastic Elastic and the two
cups on each end when he needed to communicate with Judy,
who was too far away. (pp. 87–90) They will explore
fascinating facts about sound and will identify sound as a
means of communicating.
Materials: Two foam cups (foam ones work
best), string (about three feet long or longer), and paper
clips
Directions: Ask students how they think sound
travels through the telephone when they are talking on the
phone. Tell them sound is made from vibrations and any noise
is some sort of vibration. Explain that they will make a telephone
using two foam cups, two paper clips, and a string about three
feet long. Punch a small hole in the bottom of each foam cup
and feed each end of the string into holes. Then secure the
strings by tying a knot around the paperclip inside the cup.
Working with a partner, the students can explore communication
via the new phones. Gather students around to discuss what
they experienced. What happened when the string was pulled
taut? What happened when the string was slack? What could
be done to increase the volume?
Sound is created by vibrations that travel through the air.
Of course, sound can travel through water, too. This experiment
will allow kids to “see” sound.
What happens? The grains of cereal jump.
Why? Banging on the pot creates vibrations in the metal pot.
These vibrations travel through the air. Then they travel
through the plastic covers. The plastic covers vibrate and
make the grains of cereal vibrate, too.
When you hear a sound, something is vibrating. These vibrations
create vibrations in the air that travel to your ears and
make your eardrums, and tiny bones in your ear vibrate, too.
These vibrations are transmitted to nerve cells that send
messages about sound to your brain.
Sound is a form of energy. Energy takes many forms, including
sound, light, movement, heat, and electricity. Many kinds
of energy can be converted from one form to another. Here
you can see sound energy converted to the energy of movement!
Ask students if they can think of other examples:
• Electrical energy is converted to light, sound, movement,
and heat.
• The energy of light can be collected in solar panels
and converted to electrical and heat energy.
• The movement of water can be converted into electrical
energy in generators.
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