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Unit 6: Sound Page 17
microphones that are as sensitive bounce off another. Think about a
as our ears. Our ears can pick up row of dominoes. If you put them
and tell the difference between all close together and push one
sounds as low-pitched as 20 Hz over they all fall down pretty quick.
and as high-pitched as 20,000 Hz. If you spread them out a bit, the
Some animals can hear things that row falls much more slowly. Sound
are even higher or lower pitched waves move the same way.
than that. Our ears and brain are
also very good at picking out the Sound moves faster in solid
direction a sound is coming from. objects than it does in air because
the molecules are very close
All of our senses do things together in a solid and very far
naturally that are very difficult apart in a gas. For example, sound
for science and technology to travels at about 760 mph in air,
duplicate. The human being (and 3300 mph in water, 11,400 mph in
other living things for that matter) aluminum, and 27,000 mph in
have remarkable ways of diamond!
perceiving the world around them.
The temperature of the
Speed of Sound material also makes a
difference. The colder the
Sound is a type of energy, and material, the faster the sound. This
energy moves by waves. So is why sound seems to be louder or
sound moves from one place to clearer in the winter or at night.
another by waves; longitudinal The air is a little cooler and since
waves to be more specific. So, how it’s cooler, the molecules are a
fast do sound waves travel? Well, little more tightly packed.
that’s a bit of a tricky question.
The speed of the wave depends on What exactly IS sound?
what kind of stuff the wave is
moving through. The more dense Sound is a form of energy.
(thicker) the material, the faster Energy is the ability to move
sound can travel through it. something
over a
Remember that waves move distance
because the particles bounce against a
off one another? Well, the farther force,
the particles are from one another, remember?
the longer it takes one particle to
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