[填空题]
A 55-kg person riding a bike puts all her weight on each pedal whh;x8 12q,ajoy3w bg ohen climlkdl ,wf3q/-b bing a hill. The pedalkqf- w,bl /dl3s rotate 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?