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What is the average pressure exerted on the other pedestal.

  1. Oct 27, 2008 #1
    1. The problem statement, all variables and given/known data
    An artist has designed a sculpture made from granite. The sculpture is essentially a small rectangular block whose weight is 102 kg. This centerpiece will be balanced on two granite pedestals, one at each end of the centerpiece. The pedestals are different sizes, such that one pedestal has a total area of contact with the centerpiece of 25 square centimeters and the other has an area of contact of 13 square centimeters. The first pedestal (area = 25 square centimeters) sustains an average pressure of 2kg/square centimeter. (Here "kg" means the force exerted by a mass of 1 kg.) What is the average pressure exerted on the other pedestal. Show Your Work!

    Any help would be great. Thanks!



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Oct 27, 2008 #2

    LowlyPion

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    Re: Pressure!!

    Actually any work shown would be great.

    Thanks.
     
  4. Oct 27, 2008 #3
    Re: Pressure!!

    Oh, sorry. This is the second time I have used this forum, and I am still new.

    Here is what I have so far:

    p=F/A

    First answer:

    2=F/25
    2*25=F
    F=50

    so would it be

    p=50/13
    p=3.85 kg?????
     
  5. Oct 27, 2008 #4

    LowlyPion

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    Re: Pressure!!

    Almost. According to the statement you have 2 lbs over 25 cm2 and as you point out that represents 50 lbs overall.

    But doesn't the object actually weigh 102 kg and hence doesn't the other pedestal need to provide for all of the remainder?
     
  6. Oct 27, 2008 #5
    Re: Pressure!!

    SO would it be the remaining 52 kg? Or 102 kg?
     
  7. Oct 27, 2008 #6

    LowlyPion

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    Re: Pressure!!

    Well let's think about it.

    If one end is holding up 50 kg, what will the other end hold up? What must the two ends support totally if it is at rest?
     
  8. Oct 27, 2008 #7
    Re: Pressure!!

    it would be 52 right? Because collectively they are supporting 102. So it should look like this right? Please correct me if I am wrong.

    p=52/13

    p=4kg
     
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