Short · Sound
How can sound put out a fire?
A high school student in Mexico, Ángela Karime Hernández Venegas, put out small fires with a 30 Hz hum and won gold in Indonesia. The trick isn’t really the sound: a speaker’s cone shoves air back and forth, and in a lab test a small flame blew out once it swayed about 3 mm. Half the pitch, four times the push: at 30 Hz the same sound level shoves about 1,000 times more air than at 1 kHz. The catch: it’s a puff, not a hose, so it only works on small fires up close.
Opens Sound Extinguisher Lab. Change the same thing yourself.
Transcript
This fire extinguisher has no water and no foam. Just a low hum. Ángela Hernández, a student in Mexico, won gold in Indonesia with it. The trick isn't really the sound. A speaker cone shoves air back and forth, and in a lab test, a small flame went out once it swayed about three millimeters. Now drop the pitch. Half the pitch, four times the push. At thirty hertz, the same sound level shoves a thousand times more air than at one kilohertz. The catch: it's a puff, not a hose, so it only works on small fires up close. Drop the pitch yourself at Explainer Tools dot com.