1.
[tex]Dane:\\T = 12 \ s\\\lambda = 0,06 \ km = 60 \ m\\Szukane:\\v = ?\\\\\\v = \frac{\lambda}{T}\\\\v = \frac{60 \ m}{12 \ s}\\\\\boxed{v = 5\frac{m}{s}}[/tex]
2.
[tex]Dane:\\\lamba = 1,2 \ m\\v = 24\frac{m}{s}\\Szukane:\\f = ?\\\\\\v = \frac{\lambda}{T}\\\\ale \ \ T = \frac{1}{f}\\\\v = \lambda\cdot f \ \ /:\lambda\\\\\underline{f = \frac{v}{\lambda}}\\\\f = \frac{24\frac{m}{s}}{1,2 \ m}\\\\\boxed{f = 20 \ Hz}[/tex]
3.
[tex]Dane:\\T = 5 \ s\\\lambda = 25\frac{m}{s}\\Szukane:\\\lambda = ?\\\\\\\lambda = v\cdot T\\\\\lambda = 25\frac{m}{s}\cdot5 \ s\\\\\boxed{\lambda = 125 \ m}[/tex]
