Friday 29 May 2015

Where are the dinosaurs' ears?



Try this busking!
Do you know that you can make sounds using this sound machine? It's so easy to make! You only need 3 things that you can easily get at home. Here are the materials needed. A string 40 cm long, a paper cup and a toothpick. 


Steps
1. Make a hole at the bottom of the paper cup
2. Take a string and get it through the hole under the paper cup. 
3. Tie a toothpick to the end of the string that is in the paper cup. 

This activity requires you to observe the sound produced when you pull the strings. Get your finger tips wet before you pull your fingers down the string. Do you hear a sound? If yes, try to make sounds of animals such as a clucking hen or a gecko by squeezing it at the right tempo.

Why is the sound coming from the cup louder?
This is an example of how a sounding board works. The vibrations from the string would be almost silent without the cup, but when we add the cup, it spreads the vibrations and amplifies them (makes them louder). A piano for example uses wood to act as a sounding board that makes the instrument louder.

Watch the full series of Petrosains Jurassic Adventure videos at https://www.youtube.com/playlist?list=PL3AZBh1FXS19CM0IzS1DJOjCkNyD-kAJG

So come over to #Petrosains and have fun with our current theme, Jurassic Adventure!

Posted by Ayu
Petrosains

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