1. Sound Waves and Mediums
Sound waves are longitudinal waves. They move by compressing and stretching like an inch worm.

2. Sound Waves and Mediums
Recall that sound waves are longitudinal waves and they require a medium to travel through.
A medium is any solid, liquid, or gas

3. To move through a medium, a sound wave hits a molecule causing that molecule to vibrate, which hits another molecule causing it to vibrate etc. This is how a sound waves travels, or propagates.

4. Natural Frequency
Every object vibrates. Even humans! (you just don’t notice it because the vibration is really, really small). Each object has a specific vibration frequency called the natural frequency.

5. What is Resonance?
Resonance happens when an external source vibrates the object at the object’s natural frequency, which causes that object to vibrate more and more.

6. What is Resonance?
Resonance can make an object vibrate at greater and greater amplitudes which can cause the object to shake itself apart.
Wine glass