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Weigh heavier on carpet?

  1. Jul 25, 2003 #1
    I've been struggling with this question for some time now. The question is rather simple. I'm sure most of you people have try weighing yourself on carpet and find out that it's heavier. So, why is that? How come when you weigh yourself on carpet, the measure you get is heavier than if you measure if on solid ground?

    Thanks in advance!
     
  2. jcsd
  3. Jul 25, 2003 #2

    chroot

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    I'm sure most of us have never observed any such effect.

    - Warren
     
  4. Jul 25, 2003 #3

    marcus

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    this question drives me crazy
    how can Gummicandy think that most of us have
    tried weighing ourselves on carpet?
    Gummicandy must be making this up as a clever joke to play on us.

    actually Gummi is "rubber" in German so if you give someone
    a piece of candy made of rubber that is a practical joke
    designed to catch the gullible
    it is an inventive scheme in extremely bad taste
     
  5. Jul 25, 2003 #4

    jcsd

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    That's odd, this is not the first time I have heard this question. The only answer I can think of is that the weight goes throught the centre of the scales (where the weighing mechanism is) more, rather than acting through a larger area than it would on a flat surface.
     
  6. Jul 25, 2003 #5

    chroot

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    That actually makes sense... the scale is most likely designed with some "feet" on the bottom which are supposed to be placed on a flat surface, and the device is designed to measure the pressure between its top plate and the structural members connected to those feet. If you place the scale on carpet, the scale is supported all over its bottom, not just on its feet -- and it will definitely affect its reading.

    On the other hand, it would seem to me that the scale would read low, not high, in such a circumstance.

    - Warren
     
  7. Jul 25, 2003 #6

    jcsd

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    Chroot that is the same answer I gave last time, I told them it must be due to some external factor (as an uneven surface would mean that the weight would be acting at a differnet angle to scale reducing it's vector in the direction of the scale), but seening the same question again the only explantion I can think of is that the scal;e is calibrated for weight acting through the surface evenly, but the uneven surface may mean that it acts through the weighing mechanis more than the outer edges.
     
  8. Jul 25, 2003 #7

    chroot

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    I know, that's why I said "That [your answer] actually makes sense." Sorry for not quoting you. I was just thinking aloud. :)

    - Warren
     
  9. Jul 26, 2003 #8

    HallsofIvy

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    Using the "scientific method" (heard of it?), I went to my scale on the tile bathroom floor and weighed my self (a truly horrible experience!) then moved the scale to a carpeted floor and weighed myself again. The weight on the carpet was about 8 pounds LOWER, not higher.
     
  10. Jul 26, 2003 #9

    pmb

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    Hold on. Not so fast. We don't know what kind of scale GummiCandy has.

    Here's what I'm thinking: When you step on a scale your weight shifts, i.e. you first put one foot on and then you put the other foot on. A scale may only work properly when the weight is spread evenly over the top. Perhaps what happens is that the matting of the carpet compresses unevenly as the first foot steps on and then when you put the second foot on the scale does not restore to normal.

    That's just a quick thought - i.e. not that you *reall* weigh more but that GummiCandy has a weird scale

    Pete
     
  11. Jul 27, 2003 #10
    Yeah, it means you're not afraid of doing mad things . Weighed myself on my bed. The reading was 5 kg lower than on tiled floor.
     
  12. Jul 27, 2003 #11

    EXACTLY....that is what makes sense right? On the carpet part of your weight goes to crushing (no offense ) the carpet, thereby making the apparent, overall weight of the person LESS, not more. Thanks for the 'proof' Ivy!

    fizixx
     
  13. Jul 28, 2003 #12
    My Mechanics lecturer mentioned this carpet thing as well. He said it was simply the instability of the surface under the scales.
     
  14. Jul 28, 2003 #13

    pmb

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    Wow! You mean I was right??? Cool! I love it when I take a wild shot and get it right. Thank you for brining this here.

    Pete
     
  15. Jul 28, 2003 #14
    Very humorous and entertaining posts , I especially liked Halls of Ivy's 'scientific method'.
    Unfortunately I am totally unable to participate in the research efforts here. You see, my bathroom scale kept showing a higher reading every several months. So I did what ever good scientist does when appliances go bad.....I donated it to the Salvation Army.

    However, such a drastic measure was probably premature. I realize now there was another possibility for the higher reading.....a change in the value of G !

    Creator
     
    Last edited: Jul 28, 2003
  16. Jul 28, 2003 #15
    I don't know about you, but almost all scaling devices in Israel come with the warning "to be used on flat rigid surface only". And ever since I was a child I knew that you had to weigh yourself on the floor only. :)

    Then again I also believe in the tooth-fairy, so you never know! ;)
     
  17. Nov 19, 2003 #16
    This thread looks to be a bit old, but to put you all out of your misery the reason weighing yourself on carpet gives a lighter result is because the carpet acts as an absorber, thereby taking some of the weight and reducing the load on the scales.

    Adam - I hope your mechanics lecturer isn't teaching you anything important!
     
    Last edited: Nov 19, 2003
  18. Nov 19, 2003 #17
    Amber....

    Your post is a little redundant (see my post on page 1), but always good to see reasonable responses to fun questions. :)

    f- :wink:
     
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