1. Stringed Instruments (Ex. Guitars, pianos, violins)  Vibrating the string sets up a standing wave, the vibration from the string resonate the sounding board of the instrument. The sounding board has more surface area and it creates the sound we hear.

2. Standing Wave  If we get a periodic wave on a string with a fixed end at the appropriate frequency we can create a Standing Wave  ~A wave that looks life its standing still Pluck!

3. Standing Wave  If we get a periodic wave on a string with a fixed end at the appropriate frequency we can create a Standing Wave ~A wave that looks life its standing still

4. Terminology  Nodes- points on the standing wave where there is no vibration.  There is maximum destructive interference at this point.  Antinodes- points on a standing wave with the most vibration.  There is maximum constructive interference at this point.

5. Changing the frequencies (notes) on a string  For the same note at a different octave you can force a different harmonic.  You can change the note by changing the length of the string or velocity of the wave on a string.  Velocity depends on the material, thickness, and tension of the string.  Length can be changed with your finger.

6. Fundamental frequency on a stringed instrument  fundamental frequency is the lowest natural frequency.  so it would look like this The second harmonic would look like this The third harmonic would look like this