Odpowiedź :
1.
[tex]dane:\\r = 25 \ cm = 0,25 \ m\\n = 1200\\t = 1 \ min = 60 \ s\\szukane:\\a) \ T,f = ?\\b) \ v = ?\\\\Rozwiazanie\\\\a)\\\\T = \frac{t}{n} = \frac{60 \ s}{1200} = 0,05 \ s\\\\f = \frac{1}{T} = \frac{1}{0,05 \ s} = 20 \ Hz[/tex]
[tex]b)\\\\v = \frac{2\pi r}{T}\\\\v = \frac{2\cdot3,14\cdot0,25 \ m}{0,05 \ s} = 31,4\frac{m}{s}[/tex]
2.
[tex]dane:\\d = 40 \ cm\\r = \frac{d}{2} = \frac{40 \ cm}{2} = 20 \ cm = 0,2 \ m\\n = 960\\t = 1 \ min = 60 \ s\\szukane:\\T, f = ?\\\\Rozwiazanie\\\\T = \frac{t}{n} = \frac{60 \ s}{960} = 0,0625 \ s\\\\f = \frac{n}{t} = \frac{960}{60 \ s} = 16 \ Hz[/tex]