Cycling For a touring bicyclist the drag coefficient C(f air = 2 ) is 1.00, the frontal area A is 0.463 m2, and the coefficient of rolling friction is 0.0045. The rider has mass SO.O kg, and her bike has mass 12.0 kg.
(a) To maintain a speed of 12.0m/s (about27mi/h) on a level road, what must the rider's power output to the rear wheel be?
(b) For racing, the same rider uses a different bike with coefficient of rolling friction 0.0030 and mass 9.00 kg. She also crouches down, reducing her drag coefficient to 0.88 and reducing her frontal area to 0.366 m. What must her power output to the rear wheel be then to maintain a speed of 12.0 m/s?
(c) For the situation in part (b), what power output is required to maintain a speed of 6.0 m/s? Note the great drop in power requirement when the speed is only halved. (For more on aerodynamic speed limitations for a wide variety of human-powered vehicles, see ''The Aerodynamics of Human Powered Land Vehicles," Scientific American, December 1983.)