Sound is just air or other matter that vibrates. For example, when somebody speaks, all they are really doing is using their throat to push air out, which makes the air vibrate in a way that we understand as words. The same thing happens when you drop something: the cup bounces against the floor, causing vibrations in the ground and the air around it.
What is Sound? Sound is a physical wave, which means that for
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sound to reach your friend across the room, it needs something to travel through. This could be air or water or even the wall, but in outer space where there is nothing, the sound cannot travel.
Sound travels nearly 4 times faster in water than in air!
Is sound different in Water?
Yes! Sounds are faster, louder, and travel longer in water.
This is because sound changes when it travels through different mediums. Some mediums are denser than others- they are more tightly packed, which means that there is more of it in the same space. Think of a snowball- a loosely packed snowball is flakey and full of air. Making a second snowball of the same size, but this time squeezing the snow together more tightly pushes the air out and makes it much more solid. In the second snowball, though it is of the same size, there is more snow it because the snow is more tightly packed together.
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But why is it different?
Water is more tightly packed than air, which means there would be more water than air in the same amount of space. Think of water as the tightly packed snowball and air as the loose flakey one. In water there is more matter for vibrations to travel through, so they travel faster and longer. It is like following a group of people to class. If there are not enough people to follow, you might get lost. It is the same for sound: if there are not enough things for vibrations to travel through, the noise will get lost and won’ t make it to your ears.
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