"A bicyclist can coast down a 5° hill at a constant 7.0 km/h. Assume the force of friction (air resistance) is proportional to the speed v so that Fair = cv."
(a) Calculate the value of the constant c.
(b) Calculate the average force that must be applied in order to descend the hill at 22 km/h. The mass of the cyclist plus bicycle is 79 kg.
The Attempt at a Solution
Since a=0, Ʃforce must=0.
I just can't figure out how to work around not having mass in this problem.
Any help would be greatly appreciated :)