Activity 1 Overview
Children will learn how sound is made--and how it travels--by creating
and observing a vibrating "coat hanger clanger."
Estimated Time and Age Level
Advance Preparation: 10 minutes
Activity: 30 minutes
(Ages 7-11)
Materials
(Per child)
1 metal coat hanger
1 60-cm (2-foot) piece of cotton
string
Preparation
Divide the group into pairs. Children
will need chairs with backs against which to hit their hanger devices.
They could also use the edge of a table.
Cut one 60-cm (2-foot) piece
of cotton string for each youngster. If you don't have enough metal hangers
to go around, each team can share one hanger. However, since children will
be holding one end of the string just inside their ears, they should change
the string as they pass the device around.
Set out the materials in a central
location.
Procedure
Set the stage for the activity
by asking the children what they think causes sound. They may suggest that
sound is caused by talking, musical instruments, or electronic devices
such as television sets. Write down their responses. After they do this
activity, they can revise their ideas based on what they learn.
Have the youngsters make their
"hanger clangers" by tying one end of a piece of string around
the hook part of a hanger. Then ask them to hold the other end of the string
just inside one of their ears and let the hanger swing freely against the
back of a chair. The children will hear a ringing tone that will last for
several seconds.
Now ask them again what they think
causes sound. Give them time to confer with each other and to design new
experiments to determine the cause and nature of the sound they hear, recording
their observations after each experiment. For example, they might try:
Examining the hanger after it
hits against the desk or chair. What is it doing? (Vibrating.)
Trying to alter the sound by
changing the experiment through longer or shorter swings of the hanger
or changing the hanger's shape.
Grabbing the hanger just after
it hits the chair. What happens? (The hanger stops vibrating and the sound
stops. By grabbing hold of the hanger, youngsters will be able to feel
the vibrations as well as hear them.)
Even if children don't use
the word "vibrating," they should be able to conclude that sound
has something to do with objects that move rapidly back and forth. Have
them try out other vibrating sound makers, such as plucking a stretched
rubber band. Ask them to propose and record some other ideas about what
causes sound. They'll have a chance to build on these experiences and revise
their hypotheses after the following two activities.
This activity has been copied, with permission, from the National Science Foundation server to ours, to allow faster access from our Web site. We encourage you to explore the original site.