[填空题]
(a) For a bicycle, hoj-k /;ey fli /awl(.hzz tg*1rw ism6gdla/bu 8hbxc- 0qlvr2s4 - the angular speed of the rear wheel ($\omega_R$) related to that of the pedals and front sprocket ($\omega_F$) Fig. 8–52? That is, derive a formula for ($\omega_R$)/($\omega_F$) Let $N_F$ and $N_R$ be the number of teeth on the front and rear sprockets, respectively. The teeth are spaced equally on all sprockets so that the chain meshes properly.
(b) Evaluate the ratio ($\omega_R$)/($\omega_F$) when the front and rear sprockets have 52 and 13 teeth, respectively,
(c) when they have 42 and 28 teeth.
