If the dispersion curve of the highest acoustic branch along the direction TtL can be approximated as a line with the equation v={850rns-1)k, where v = frequency and k = wavenumber. Calculate for the speed of sound for this branch (in m/ s). Lattice parameter: a = 066 a: 101\" m Density: 5.05 gi'cm1| Phonon dispersion diagram {note: this is in frequency not angular frequency\" A H g :r. u i: a =i 5" 1:; :3: X K scaled wave vector