[tex]Dane:\\\lambda = 17 \ cm =0,17 \ m\\v = 340\frac{m}{s} \ - \ predkosc \ fali \ w \ powietrzu\\Szukane:\\f = ?\\\\v = \frac{\lambda}{T}\\\\f = \frac{1}{T}\\\\v = \lambda \cdot f \ \ /:\lambda\\\\\underline{f = \frac{v}{\lambda}}\\\\f = \frac{340\frac{m}{s}}{0,17 \ m}\\\\\boxed{f = 2 \ 000 \ Hz = 2 \ kHz}\\\\(1 \ kH = 1000 \ Hz)[/tex]
