# A bicyclist of mass 75 kg (including the bicycle) can coast down a 4.0° hill at a steady speed of 12

A bicyclist of mass 75 kg (including the

bicycle) can coast down a 4.0° hill at a steady speed of 12 km/h. Pumping hard,

the cyclist can descend the hill at a speed of 32 km/h. Using the same power,

at what speed can the cyclist climb the same hill? Assume the force of friction

is proportional to the square of the speed v; that is, Ffr = bv2,

where b is a constant.