[填空题]
A 55-kg person riding a bike puts an;;o :( bgy+w1p gczgowc4f 7u fi,jj8ll her wxpn +s mfu hffztcqw--:f+8 **eight on each pedal when climbing a hill. The pedals rotate in a circle of -pffmw*+*hq8+ z fxtus:-n f cradius 17 cm. (a) What is the maximum torque she exerts? $m \cdot N$ (b) How could she exert more torque?