Things to adapt and change
- try to race sound
- test the speed of sound against the speed of light
- become a human sound chain - squeeze hands
What is happening in this picture?
What happens in this film?
What do you hear and how is this sound made?
Contrary to popular belief, the loud noise you hear when Latex balloons burst is not due to the sudden release of high pressure gas contained inside the balloon...such pressure isn't all that great. Rather, the BANG is caused by the tightly stretched ends of the torn Latex balloon pieces exceeding the speed of sound (and, thus, creating a "sonic boom" ) as they quickly snap back to their pre-inflated size. Specifically, when a tiny crack develops in the surface of an inflated Latex balloon (such as when a pin pricks it) the resulting rapid release of energy stored in the stretched Latex accelerates the crack to near the speed of sound in rubber. Since this speed is much higher than the speed of sound in air, the running crack actually breaks the sound barrier! The loudness of the bang is usually dependent on how much the Latex is stretched before it bursts. This is why even small Latex balloons stretched to their limits will often make a much louder BANG when they burst than a larger balloon that is not stretched as tightly.
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What did you learn during this investigation?
What surprised you?
What new thinking or ideas did you have?
What was your favourite experiment?
What did you find hard?