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: Does it make since if it takes 675 food Calories to lift me up 17 ft?

  1. Oct 17, 2005 #1
    does it make since if it takes 675 food Calories to lift me up 17 ft
    look below

    *IGNORING HORIZONTAL DISTANCE*
    i gotta figure out how much work is done to get myself up from my class to the cafeteria which is 17 ft in vertical hieght
    PE=mgh
    my weight is 120 lbs i converted to mass
    54.545 Kg which makes 54,545 g

    multiply that by gravity 10 (yes i know 9.8 but my teacher is stupid and confusing)

    then multiply that by hieght which is 17 ft but its got to be Meters so i did 5.1816

    so i get Work = 2,826,303.72 Joules
    got to convert that to FOOD Cal and i got around 675
    with this conversion
    J * (1 cal/4.187J) * (1 Food Cal/1,000cal) = Food Calories

    so does that makes since it takes 675 food Calories to lift me up 17 ft
     
  2. jcsd
  3. Oct 17, 2005 #2
    The standard unit for mass is kilograms. Your answer is 1000 times too big because you converted kilograms to grams.
     
  4. Oct 17, 2005 #3

    Pengwuino

    User Avatar
    Gold Member

    mass is in kilograms
     
  5. Oct 18, 2005 #4
    thanks now i got a more resonable answer
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook