[latex]V = 180 frac{km}{h } = 180* frac{1000 m }{3600 s } = 50 frac{m}{s} [/latex] [latex]f = 40 Hz = 40 frac{1}{s} [/latex] [latex]V = frac{2 pi r}{T} [/latex] [latex]T = frac{1}{f} [/latex] [latex]V = 2 pi rf/: 2 pi f[/latex] [latex]r = frac{V}{2 pi f} [/latex] [latex]r = frac{50 frac{m}{s} }{2 *3,14 * 40 frac{1}{s} } = frac{50 m}{251,2 } = 0,2 m [/latex] [latex]d = 2r [/latex] [latex]d = 2 * 0,2 m = 0,4 m [/latex]
[latex]dane:\v = 180frac{km}{h} = 180*frac{1000m}{3600s} = 50frac{m}{s}\f = 40 Hz = 40 frac{1}{1s}\ pi =3,14\szukane:\d = ?[/latex] [latex]v = 2 pi rf /:2 pi f\\r = frac{v}{2 pi f}\\r=frac{50frac{m}{s}}{2*3,14*40frac{1}{s}} = 0,199 m\\r approx0,2 m\\d = 2r = 2*0,2m = 0,4 m[/latex] Odp. Średnica koła ma długość 0,4 m.
