Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Drag force and friction force

  1. Feb 20, 2009 #1
    1. The problem statement, all variables and given/known data

    For a touring bicyclist the drag coefficient C(where f of air = 0.5CApv^2) is 1.04, the frontal area A is 0.462 , and the coefficient of rolling friction is 4.60×10−3. The rider has mass 53.0kg, and her bike has mass 11.1kg.
    Note: p is density of air (1.2kg/m^3)

    To maintain a speed of 11.7m/s on a level road, what must the rider's power output to the rear wheel be?

    The attempt at a solution

    Total force = friction force + drag force
    Power = total force x velocity = 459.6W

    which is not correct.
     
  2. jcsd
  3. Feb 20, 2009 #2

    LowlyPion

    User Avatar
    Homework Helper

    I would calculate it the same way, but with more precision. I got an answer close but possibly enough dissimilar?
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook