[填空题]
A 55-kg person riding a bike puts all rz i)/rht4-s k:pu5sn her weight on each pe0 pu9 fro4x(lpdal when climbing a hill. The pedals l pr(o9uxp 4f0rotate in a circle of radius 17 cm. (a) What is the maximum torque she exerts? $m \cdot N$ (b) How could she exert more torque?