Answer:
Sound is a vibration, or wave, that travels through the air. Sound waves are invisible to our eyes; unless we find a way to make the sound waves move something that we can see. In this activity, your child will use different noise-making objects to cause sound waves and make sand visibly move.
Sound wave can be described by five characteristics: Wavelength, Amplitude, Time-Period, Frequency and Velocity or Speed. The minimum distance in which a sound wave repeats itself is called its wavelength.
Explanation:
When the vibrating air hits your eardrum, it causes your eardrum to vibrate, just as the balloon did. These vibrations are transferred through the tiny bones in your ear to the inner ear. These vibrations are detected by nerves, which send impulses that your brain "hears" as sound.
