The assignment was to create a weighing scale. Some used springs, some used rubber bands, I used guitar strings.

Using the equations above, I built a scale that used tension on a guitar string as an indicator for the mass of a load. 

There are 3 variables that determine the pitch a string will emit when plucked;

• Length of the String
• Mass per unit length of the string 
• Tension of the string

Using a string of known mass and a fixed section that will be vibrating, the tension under load can be determined by the pitch of the measuring string compared to a reference string of a set tension and mass, but varying length of the vibrating portion using a slide. 

The results were surprisingly accurate considering the materials used and short development period.