posted by physics .
Assume a cyclist of weight mg can exert a force on the pedals equal to 0.90 mg on the average. If the pedals rotate in a circle of radius 18 cm, the wheels have a radius of 34 cm, and the front and back sprockets on which the chain runs have 42 and 19 teeth respectively (Fig. 7-32), determine the maximum steepness of hill the cyclist can climb at constant speeds. Assume the mass of the bike is 18 kg and that of the rider is 70 kg. Ignore friction.