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Homework Help: Finding center of gravity

  1. Jan 27, 2008 #1
    1. The problem statement, all variables and given/known data

    A 160cm tall person lies on a light(massless) board which is supported by two scales , on under the feet and the beneath the top of the head. the scale under his feet read 29.4kg
    and the scale under his head reads 32.8 kg ....... where is the center of gravity of this person??

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Jan 27, 2008 #2
    What have you tried so far? It's always a good idea to start with a picture and a force-body diagram.
  4. Jan 28, 2008 #3
    the simplest method to solve the problem is to calculate net torque abt the center of mass of person [take it as xi^+ yj^] from both the sides.then calculate the difference in the torques to get the value which gives the distance from the center of mass.

    first proceed with the first step and update me of the progress.
  5. Jan 28, 2008 #4
    huh ???????? i don't understand
  6. Jan 28, 2008 #5
    what u mean is ....... take the torques from each side ....... and use the very middle of the person as the pivot point??? am i correct ???
    if so i got
    t1 = 32.8 * 80
    = 2624
    t2=29.4 * 80
    = 2352
    does that look right??
  7. Jan 29, 2008 #6
    comeon..how can ya take the distance as 80 cm??

    take it as .80m

    the new relations are;


  8. Jan 29, 2008 #7
    yah alright i get that ......... next step??
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