If you have seen some war movies, you must have felt an on-screen explosion? If so, you know that sound can be a moving experience. Do you remember which sounds shook you the most? Was it the high-pitched whirls or the booming low pitches? While you are remembering, here’s a smaller-scale rumbling (but one that’s easy to observe).
Things Required:
Sound system
Foil pie pan
Puffed cereal grains
Directions:
Gently lie a speaker cabinet on its back so that its speaker may face upwards. Balance a foil pie plate on top of the speaker grill.
Pour about fifty grains of puffed cereal onto the pie plate. Make sure the sound system is “off,” with the volume turned down. Switch on the system. Slowly, crank up the volume and watch what happens to the cereal!
This Is What Happens:
Sound is a form of energy. It consists of vibrations that are passed from particle to particle. In air, the vibrations of sound are transferred by the particles of gas that are too small to see.
The sound produced by the speaker caused air particles to vibrate. The energy of the vibration spread out and struck the bottom of the pan. The large (and light) bottom of the pan was struck by a good deal of sound energy. This energy caused the pan to vibrate. The energy of vibration was then transferred to the cereal grains. As they became energized, the puffs jumped to the beat.
