A guitar string is fixed at both ends. The mass of the string is $0\mathrm{.}0032$ kg$,$ and the length is $1\mathrm{.}19$m$.$ The string is under tension of $55\mathrm{.}0$N$.($a$)$ Find the wavelength and frequency of the first two modes of standing waves. Suppose the tension is increased to $75\mathrm{.}0$ N$.($b$)$ Also find the wavelength and frequenct of the first two modes of standing waves under this new tension.