How does sound travel?

sound 3.jpg

How does sound travel?

Exploring the science of sound will blow your mind! All you need is a wire coat hanger and some string or yarn.

Materials:

            One wire coat hanger

            Two pieces of string or yarn cut about 3 feet long.

Instructions:

            Tie the two pieces of string, one each to the bottom wire of the coat hanger.

            Wrap the string ends around your two index fingers and place your fingers into your ears.

sound.jpg

sound 2.jpg

            Let the hanger swing and bump it into a hard surface, such as a chair or table. What do you hear? How does the sound differ if you don’t put your fingers in your ears?

What’s going on:

Sound waves are created by the vibration of an object (the wire hanger and string).  When vibrations travel to your eardrum, your brain interprets the vibrations as sound. The sound waves can move through air, liquids and solids. When we listen to the hanger hit the table with the string to our ears, the sound waves are traveling through the solid string and hanger. Since sound waves travel more quickly through solids, we can hear the sound more clearly. When we bang the hanger without putting the string to our ears, the sound waves are traveling through air, which makes the sound softer by the time it gets to our ears.