P4 sound and pitches

1. Sound is an energy. It travels in waves. To make a sound we
need to produce vibrations such as hitting a drum or banging
a table.
Vibrations travel through solids, liquids or gases and reach
our ears. If there are a lot of vibrations and a lot of energy
the noise is loud. If there is only a little energy the sounds
is quiet.
Sound can travel better through some materials than
others. Many homes have carpets upstairs as it reduces the
sound more than wooden floarboards. Sound can travel
through water. Dolphins can communicate with each other
through many mile of water.
The only thing sound cannot travel through is a vacuum (a
complete empty space with no air). In space there is no air
so sound cannot travel. When we hear sound it can be a high
sound or low sound. This is called the pitch.

2. Directions : Use what you have learned about sound to compelte the sentence
below.
Word Bank
1. _____________ is made by vibrations.
2. Vibrations happen when something moves ____________ quickly
3. Sound _________ travel through the air
4. When sound waves are fast the sound has _______________
5. When sound waves are slow, the sound has ______________
What is amplitude ?
Amplitude is description of the sound wave’s strength. As the amplitude of
a sound wave decreases, the volume of the sound decreases. Amplitude, or
wave height, decreases over time if no more energy or force is put back
into the system. Strum a guitar string or hit a piano key one time and the
volume of the sound gets less and less over time. One way computers
represent sound waves is show below. Over time, the amplitude, or wave
height, decreases if no more energy is put into the system. The results in
less and less volume overtime.
Low pitch waves high pitch back-and-forth sound

3. Student Name _________________
Why does the glass shatter ?
1. Singer tops the glass and listens
Before singing
First, I observed that
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4. 2. Singer sings near glass
During singing
Next, when the singer was singing I observed that
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5. 3. Glass shatters. Singer stops singing
After singing
Finally, when the singer stopped singing I observed that
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I think this happened because
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