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: Riding against the wind- complicated bicycle problem

  1. Dec 12, 2009 #1
    1. The problem statement, all variables and given/known data

    A wind is blowing against a bicycle rider at a velocity of v0 = 10m/s. The rider is driving with the same power as in the windless weather, but he requires twice as much time to pass the straight part of the road as in the windless weather. With what velocity is he riding? With how much power should he ride if he if he wanted to ride with the same speed as in the windless weather? Assume that the cyclist is only overcomes the force of air resistance.

    2. Relevant equations

    P= W/t
    P(t)= F(t) v(t)
    PE= mgh
    KE= mv²/2

    3. The attempt at a solution

    First part: With what velocity is he riding?

    KE(wind)=KE(biker)
    mv(wind)²/2= mv(biker)²/2
    v(wind)= v(biker)
    v(biker)= 10 m/s

    Is my attempt correct?
    And I don’t know how to continue. What about the second part?
    Can someone, please help me
    ?
     
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted