[填空题]
A 55-kg person riding a yb4upb )+3x76ye1qg z 3jmwm obike puts all her weii(.s3s .m gyjrnu .fi8ght on each pedal when climbing a hill. The pedals rotate in a ci(gfyu3r8i..n.s imj srcle of radius 17 cm. (a) What is the maximum torque she exerts? $m \cdot N$ (b) How could she exert more torque?