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

Work done on a stationary bicycle?

Tags:
  1. Feb 12, 2016 #1
    So when someone is simply cycling on a stationary bike, is that person doing any work? Because work is Force * distance. But there's no distance here, right?

    Is work simply the energy then?
     
  2. jcsd
  3. Feb 12, 2016 #2

    berkeman

    User Avatar

    Staff: Mentor

    You are generating force with your legs to turn the pedals & crankshaft against a reactive force. Stationary bikes are designed to have a configurable resistance that they offer to your pedaling. :smile:
     
  4. Feb 12, 2016 #3

    CWatters

    User Avatar
    Science Advisor
    Homework Helper

    Stationary exercise bikes usually turn the energy you produce into heat, perhaps heating a mass of air...

    Work = mass * specific heat capacity * temperature change.
     
  5. Feb 12, 2016 #4
    But I thought work had to have distance?

    So how come, when you cycle a regular bicycle on a road, you don't account for temperature change? You just do F*distance
     
  6. Feb 12, 2016 #5

    jbriggs444

    User Avatar
    Science Advisor

    The pedals are moving.
     
  7. Feb 13, 2016 #6

    CWatters

    User Avatar
    Science Advisor
    Homework Helper

    Energy is always conserved, its just converted from one form to another. The equations you can use to calculate the flow of energy in a system depends on the form of energy at that point in the system.

    When you cycle a regular bike some of the total force is due to air resistance. Stirring the air heats it up. No need to account for this separately because its already included in the total force. Another part of the total force is due to rolling resistance an that heats the tyres. Again no need to account for that separately because its also included in the total force.
     
  8. Feb 13, 2016 #7

    CWatters

    User Avatar
    Science Advisor
    Homework Helper

    Clearly there are times when you would like to know what fraction of force * distance is due to drag, rolling resistance, bearing friction etc and account for all the components separately.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Work done on a stationary bicycle?
  1. Work is done? (Replies: 8)

  2. Work is done or not? (Replies: 16)

  3. Work done (Replies: 4)

Loading...