Did you know that ultrasonic sound can serve as a cleanser? When ultrasonic sound passes through water, the sound waves cause the
water to vibrate rapidly. Ultrasonic washing machines use this principle to shake dirt loose from clothing placed in the water. The same motion is
used for cleaning small metal parts. These are placed in a cleaning fluid agitated by vibrating quartz. The action shakes the dirt and grease off the
metal quickly.
Ultrasonic sound is also used to remove smoke from the air. Standing waves are produced in the air by means of reflectors. The resulting
vibrations make the small particles of soot in the air move toward the nodes of the waves. These particles collide and stick to each other. They
form larger particles which keep growing until they are heavy enough to fall to the ground.
Standing sound waves are produced in the air by means of
1. smoke.
2. quartz.
3. reflectors.
4 collisions.
