[填空题]
A 55-kg person riding a bike puts all her weight ;a9j k7/ct*h3f0b+m f yazjocon each pedal when clim ug/hskr v4q3 /bbh+w e9oe5pt +m9o;pcuea8 3bing a hill. The pedab3h 9qpmu9wb/3v8uheo t++; 5r 4s k co/aeegpls 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?