The strings of a violin are tuned to the tones `G , D , A and E` which are separated by a fifth from one another . That is `f(D) = 1.5 (G) , f(A) = 1.5 f(D) = 400 Hz and f(E ) = 1.5 f(A)`. The distance between the two fixed points , the bridge at the scroll and over the body of the instrument is `0.25 m`. The tension on the string `E is 90 N`. The mass per unit length of string `E` is nearly