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

Losing weight using Physiscs

  1. Sep 21, 2012 #1
    so im going to use the potential energy law e=mgh to lose joules(fat) the problem is that whats the energy effiency of the body i cant find that anywhere. im climbing a 22.5m apartment building and my weight is 114kgs (im not fat just big boned)
  2. jcsd
  3. Sep 21, 2012 #2


    User Avatar
    Science Advisor
    Homework Helper

    Why not assume it's 100% efficient?

    E = 114 * 9.8 * 22.5m = 25,000

    1J = 0.24 calories

    so 25,000J = 6000 Calories.

    The bad news is that "calories" on a packet of food are actually kilocalories.

    So one trip to the top burns just 6 food calories

  4. Sep 21, 2012 #3


    User Avatar
    Science Advisor
    Homework Helper

    Google suggest you should assume the body is about 20% efficient so multiply by 5. One trip up is about 30 food calories. Looks like a BigMac is about 490 food calories or 16 trips up.

    Edit: Got to laugh. Google has already changed the banner advert I see at the top of the page from one adbertising solar panels to one advertising a weight loss system.
  5. Sep 25, 2012 #4
    16 trips just for a bigmac???!!! no wonder everybody is fat.
  6. Sep 25, 2012 #5
    Climbing stairs is incredibly tedious. You're better off doing something more enjoyable which you will commit to doing for a long period of time, and it's absolutely necessary to eat properly.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook