Vibration Science: Tuning Forks, Pasta Resonance, and Straw Trombones
This is the full lesson plan that serves as the linchpin for the AAPT/ASA Vibration Science Digi Kit.  It explores pitch, frequency, amplitude, and resonance phenomena through three hands-on activities that can be quickly and inexpensively set up in the middle school classroom. It blends a digital simulation of wave phenomena with physical models that include spaghetti resonators and straw trombones. The lesson was designed to help students gain deeper understanding of how vibrations create sound in various media and how sound energy is transferred or transported in tuning forks and musical instruments. It's appropriate for students with little or no background in wave behavior or properties of waves.
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Acoustical Society of America: Wave Basics
This lesson provides explicit instructions for using the PhET simulation "Wave on a String" to model amplitude and frequency and explore how damping and tension affect the speed of a wave. It's appropriate for a conceptual physics or 9th Grade physical science course. It could be a great way to introduce a unit on Vibration or Sound.
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Acoustical Society of America: Tuning Fork Discovery

This creative lesson engages students in the fun of exploring tuning forks to promote understanding of scientific concepts that include those below:
     1. Relationship between frequency and pitch
     2. Relationship between pitch and length of a vibrating column
     3. Energy transfer in vibrating objects
     4. Resonance -- when one object vibrating at the same natural frequency of a second object forces that second object into vibrational motion.

You will need one tuning fork for each collaborative group. Take care that tuning forks are uniform (the same brand) with no turning knobs on the ends. The lesson contains background information, key terminology, and extension ideas.
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