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Speed
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Speed
of Sound:
Overview: Parents
can help their students with this exercise using readily available items
to figure the rough speed of sound. Incorporate this into your regular
lessons on sound.
Teacher Preparation: Optional handout sheet describing the procedure
below.
Procedure Ideas:
 Discuss the phenomenon
of sound traveling much slower than light, hence seeing distant actions
before hearing their accompanying sounds.
 Explain how knowing
the distance from an action and timing the length of time a sound takes
to reach us enables us to calculate the speed the sound is traveling
at.
 Brainstorm with
students situations where the time delay can be confusing, such as at
sporting events or public concerts.
 Brainstorm with
students ways they can estimate the speed with their parents. Hint:
An automobile is an easy way. Drive from point A to B, using the
odometer to go a fixed distance such as a quarter mile or half kilometer.
Using a stopwatch (many digital wristwatches have one) clock the time
delay of slamming a door.
 Remember to have
students do the experiment several times to obtain consistency.
Options/Variations:
Discuss the variable of temperature as it affects the speed of sound;
at 32F/0C the speed is 1085 feet per second. At 212F/100C the speed is
1268 feet per second.

