Riding a bicycle at a constant speed requires the rider to provide enough constant force to the pedals to overcome the resistance forces. To make this problem easier to calculate, assume that there are only two resistance forces: rolling friction of the bicycle tires on the surface, and air resistance of the bicycle and rider. The additional friction of an uneven surface, the bearings in the wheel, and so forth are neglected - imagine a brand new bicycle ride along the Burke-Gilman Trail on a windless summer day. a. Question: How much power must the rider supply to keep their ride (mass of bicycle rider = 100 kg) at a constant speed of 20. mph? Assume all values have two sig figs of precision. Approach: Find a simple mathematical relationship between force and power. Then find the total force the rider must supply. Start with the equation for calculating the rolling friction; a couple of the values are obvious but you will need to find a rolling (or dynamic) coefficient of friction of a bicycle tire. Make sure the units make sense. This should be a pretty small number. For air resistance, the standard formula is Fair = cd