Hundreds and Thousands |
Make sprinkles dance using sound!
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Curriculum Links KS2 Sound and Vibration
Download the experiment guide:
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You will need a mixing bowl, plastic food wrap, paper, sticky tape, some sprinkles, a portable speaker and a mobile phone.
What is going on? Sounds are caused when objects vibrate, making the stuff around them (such as the air) vibrate. The vibrations travel as the vibrating air particles cause the ones next to them to vibrate and so on. When the vibrations reach our ears they make our eardrums and the tiny bones connected to them vibrate. Information about the vibration is carried to our brain by our auditory nerve, and our brain interprets the signal as sound.
In the bowl, the sound from the speaker causes the air particles to vibrate. When the vibrations reach the plastic wrap it vibrates like the membrane of our eardrums. These vibrations cause the sprinkles to shake about. Louder sounds cause stronger vibrations and more movement than softer sounds.
If you don't have a speaker you can try clapping or banging a saucepan or baking sheet with a wooden spoon, as close as you can to the bowl without touching it.
If you don't have any sprinkles, try rice, lentils or small seeds.
- Place the speaker in the bowl and cover the bowl tightly with the plastic wrap.
- Tape a strip of paper around the edge of the bowl, or secure hook and loop tape around the rim to prevent the sprinkles from falling off.
- Pour some sprinkles on top of the wrap.
- Use your phone to play sounds through the speaker. What happens to the sprinkles?
- Experiment with different sounds (you could try loud and soft sounds, music with lots of bass or lots of treble, or use a free tone generating app to try out different frequencies). Which sounds cause the most movement?
What is going on? Sounds are caused when objects vibrate, making the stuff around them (such as the air) vibrate. The vibrations travel as the vibrating air particles cause the ones next to them to vibrate and so on. When the vibrations reach our ears they make our eardrums and the tiny bones connected to them vibrate. Information about the vibration is carried to our brain by our auditory nerve, and our brain interprets the signal as sound.
In the bowl, the sound from the speaker causes the air particles to vibrate. When the vibrations reach the plastic wrap it vibrates like the membrane of our eardrums. These vibrations cause the sprinkles to shake about. Louder sounds cause stronger vibrations and more movement than softer sounds.
If you don't have a speaker you can try clapping or banging a saucepan or baking sheet with a wooden spoon, as close as you can to the bowl without touching it.
If you don't have any sprinkles, try rice, lentils or small seeds.