Odpowiedź :
[tex]r = 50 \ cm = 0,5 \ m\\f = 10 \ Hz = 10 \ \frac{1}{s}\\\\\\a)\\T = \frac{1}{f} = \frac{1}{10 \ \frac{1}{s}} = \boxed{0,1 \ s}\\\\b)\\v = 2\pi rf = 2\cdot3,14\cdot0,5 \ m\cdot10 \ \frac{1}{s} = \boxed{31,4\frac{m}{s}}[/tex]
[tex]r = 50 \ cm = 0,5 \ m\\f = 10 \ Hz = 10 \ \frac{1}{s}\\\\\\a)\\T = \frac{1}{f} = \frac{1}{10 \ \frac{1}{s}} = \boxed{0,1 \ s}\\\\b)\\v = 2\pi rf = 2\cdot3,14\cdot0,5 \ m\cdot10 \ \frac{1}{s} = \boxed{31,4\frac{m}{s}}[/tex]