[填空题]
A 55-kg person riding a bik.o.a* ta (9bmvqxwlc9 e puts7;o.eucze 5rg all her weight on each pedal when climbing a hill. The pedals rotate in a cg7 .zu5roe ;ecircle of radius 17 cm. (a) What is the maximum torque she exerts? $m \cdot N$ (b) How could she exert more torque?