Pitch and Volume
Since we had done previous activities with sound, kids were familiar of the fact that sound waves travel through air are longitudinal waves with compression and rarefaction. Just to brush up their memory, we reviewed some of the concepts such as How the sound is produced? Sound is produced when something vibrates. The vibrating body produces sound waves or vibrations in the medium (water, air, etc) around it to vibrate. Vibrations in air are called longitudinal waves, which we are able to hear. These sound waves have high and low pressure areas called compression and rarefaction. Why is the sound called longitudinal wave? Sound waves are called longitudinal, because particles of the medium through which sound travels moves parallel to the direction of the sound waves. Here, with the help of the slinky it can be shown how sound waves move. To make it simple, for the kids to understand pitch and volume, the following demonstration can be done using an elastic rubber band