1 cal = 2,54 cm
v = 25 km/h = 6,94 m/s
[tex]d_1 - srednica_.obrczy = 26 cal = 26*2,54cm=66,04cm=0,6604m[/tex]
[tex]d - srednica_.kola = d_1 + 0,12m= 0,6604+0,12 = 0,7804m[/tex]
[tex]r - promien_.kola= \frac{d}{2} = \frac{0,7804}{2} =0,3902m[/tex]
[tex]f = czestotliwosc = \frac{v}{2*pi*r} = \frac{6,94}{2*3,14*0,3902} = 2,83Hz[/tex]