1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Energy problem

  1. Mar 1, 2005 #1
    Assuming an energy equivalent for your food of 2.1 x 107 J/kg, calculate the amount of food needed to walk a distance of 30 km at a rate of 5 km/hr?
  2. jcsd
  3. Mar 1, 2005 #2
    You can't answer that one without more information.

    You need to know how many watts of power (joules per second) the person uses when walking at that speed.

    Travelling at a constant speed needn't use any energy at all (unless it is uphill, or against some resisting force). Obviously a walking person does use energy to do so, but without knowing the rate of energy usage (power) then there is no way to answer the question.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Energy problem
  1. Energy bike problem (Replies: 6)

  2. Energy problem (Replies: 1)

  3. Energy Problem (Replies: 1)

  4. Energy problems (Replies: 1)

  5. Energy Problem (Replies: 1)