Slinky tm or similar toy
Activity
Stretch
the Slinky out on the floor or a table to about three to four meters
with a partner firmly holding the other end. One of you represents
the sound source and the other represents the sound receiver (the
ear). Caution: use the Slinky carefully so it does not get kinked.
The
sound source person gives the Slinky a push. What happens?
Put
more force into the push. Does the wave change?
Do
the coils of the Slinky travel away from one person a toward the other?
What is moving from one end of the Slinky to the other?
What
enables us to hear sounds?
What
happens when a sound wave reaches our ear?
How
is sound transmitted to the brain?
Challenge:
Research how crickets, frogs, bats or snakes hear.
Science
Notes
A
slinky can model sound waves traveling through solids, liquids or
gases. Each coil represents a molecule of the material. With a push,
the coils compress against each other. The compression travels to
the other end of the Slinky as a wave. Sound travels through solids,
l;liquids and gases as a compression wave. Energy is transmitted through
the coils and travels from source to receiver.
When
an object begins to vibrate, the molecules next to it are compressed
or pushed together. This compresses molecules further out. When the
object moves back, a space in the air is created next to the object.
The first molecules of air expand to fill this space, causing molecules
further out to expand too. This compression and expansion of the air
molecules is called a sound wave.
discussions