A typical value for the coefficent of quadratic air resistance on a cyclist is around c=0.20 N/m(m/s)2. Assuming thath the total mass (cyclist plust cycle) is m = 80 kg and that at t = 0 the cyclist has an intial speed v=20m/s (abouit 45 mi/h) and starts to coast to a stop under the influence of air resistance, find the characteristic time τ=m/cvo. How long will it take him to slow to 15 m/s? What about 10 m/s? And 5 m/s? (Below about 5 m/s, it is certainly not reasonable to ignore friction, so there is no point pursuing this calculation to lower speeds.)