[填空题]
A 55-kg person riding a bike puts all her weigh )obb ukv/-m glq);:tzgcz*)it on each pq (zd ,fg-bvi:edal when climbing a hillz (bqf:v, dgi-. The pedals 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?