Sound - String Instruments

Question 1

string instruments

Answer 1

• If you have a string held at both ends, and you send a wave down the string, it will reflect at the ends and travel back and forth along the string. If the wavelength (or frequency) of the wave is just right, the overlapping waves in the string can create a Standing Wave with a big amplitude and a certain number of loops. These only occur at very specific frequencies.
• Stringed instruments, like guitars, violins, and pianos, use standing waves to create oscillations at a specific frequency, which creates a specific pitch or note. If you pluck a string on an instrument, it naturally sets up a standing wave with only one loop. You may recall, the frequency of a standing wave with one loop is called the “Fundamental Frequency”
• To make notes at different frequencies, an instrument can either change the speed of the wave, or its length. You can change the speed by changing the tension or force in the string; tightening the string increases the speed, which increases the frequency. You can also change the speed by using fatter or skinnier strings. The skinnier the string, the faster the wave, and the higher the frequency it creates.