2.
a)
[tex]n = 30\\t = 2 \ min = 2\cdot60 \ s = 120 \ s\\\\f = \frac{n}{t}\\\\f = \frac{30}{120 \ s}\\\\\boxed{f = 0,25 \ Hz}[/tex]
b)
[tex]n = 3 \ 600\\t = 0,5 \ h = 0,5\cdot3600 \ s = 1 \ 800 \ s\\\\f = \frac{n}{t}\\\\f = \frac{3600}{1800 \ s}\\\\\boxed{f = 2 \ Hz}[/tex]
3.
[tex]DAne:\\n = 15\\t = 1 \ min = 60 \ s\\\lambda = 16 \ m\\Szukane:\\v = ?\\\\\\T = \frac{t}{n} = \frac{60 \ s}{15} = 4 \ s\\\\v =\frac{ \lambda}{T}\\\\v = \frac{16 \ m}{4 \ s}\\\\\boxed{v = 4\frac{m}{s}}[/tex]
