Noisy vibrations make a clucking sound
Want to surprise your friends and family? With a bit of practice, you can make this cup cluck like a chicken!
If your cup doesn’t cluck, there are plenty of things you can try!
As you start to pull, pressure on the string and sponge causes them to stick together. But as you pull harder and harder, the string stretches, the sponge bends and even the bottom of the cup starts to flex.
Eventually though, the force is too much and the string starts to slide through the sponge. The string relaxes, the sponge unbends, and the cup returns to normal while the sliding continues.
If everything is just right, the string and sponge will stick again just as everything unbends. Then it slips and sticks over and over, many times every second.
The slipping and sticking vibrates the string. But most of the noise comes from the bottom of the cup. It gets pulled every time the string sticks, and released every time it slips. The bottom of the cup vibrates back and forth like a speaker cone! The rest of the cup also works as a horn to direct and amplify the sound even further.
Have you ever pushed a chair across the floor, making a loud noise the whole time? Believe it or not, it’s making noise in a similar way to your clucking cup. Both are a matter of sticking and releasing, causing noisy vibrations.
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17 September, 2021 at 1:24 pm
Add an orange paper comb and some google eyes for lots more fun – I used to make these with my class every Easter. You can even get a chook choir going with some appropriate chicken dance music.