I'm not to sure what the question is but it sounds like you are describing the Law of Conservation of Energy: stating that energy can't be created nor destroyed, but instead transferred or conserved.
Phase is an expression related to vibration. Just like phase 1 phase 2, phase 3 etc, it's basically a stage a particle is in, in its travel. Same phase means all the particles are in same stage of traveling, therfore same speed and direction.
Answer:
<em>The velocity of sound in the guitar string = 129.99 m/s</em>
Explanation:
Harmonics: A harmonic is a note with frequency equal to an integral multiple of that of the fundamental frequency.
<em>Note:</em> The harmonics of a string is the same as the harmonics of an open pipe.
f₆ = 3v/l ............................ Equation 1
making v the subject of the equation,
v = f₆l/3 ......................... Equation 2
Where f₆ = Is the sixth harmonics of the the string, v = velocity of sound in the guitar string, l = length of the guitar string.
<em>Given: </em>f₆ = 557.14 Hz, l = 70 cm = 0.7 m.
Substituting into equation 2
v = (557.14×0.7)/3
<em>v = 129.99 m/s</em>
<em>Thus the velocity of sound in the guitar string = 129.99 m/s</em>