Friday, 12 February 2016

More investigations with sound

Today we continued our investigations with sound.
Today we tested whether sounds can travel through a solid like a piece of string.
We took ordinary spoons with string tied around them..
When you hit these spoons off a solid object like a table they make a clanging noise.
However, if you hit the spoons off the solid object again and this time hold the string to the bone outside your ear you can hear church bells.
We discovered that the size of the spoon influences the pitch of the note you can hear:
small spoons give a high note while big spoons and ladels give very low notes.
Teacher had a tuning fork. 
She showed us how to use it and we listened to see did it make the same note each time we hit it (it did).
When we got the prongs vibrating (shaking) we put the tuning fork into water, or up to dishes of rice or peas.  The results were amazing:
Look at what happens when you put the tuning fork against (an air filled) ping pong ball:
We also used sound tubes to get the air vibrating to make different notes.

What an interesting afternoon working with sound!!!

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