1. Length formula: If the tension of a vibrating wire and the mass of a single length remain unchanged , the frequency of the wire is disproportionate to the length. 2. Tension formula: If the length and mass of a vibrating wire are constant , the frequency of the wire is proportional to the square root of the tension. 3. Formula of mass: If the length and tension of a vibrating wire remain unchanged , the frequency of the wire is disproportionate to the square root of the mass of a single length.