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Pressure from contact surface

  1. Nov 2, 2014 #1
    1. The problem statement, all variables and given/known data
    The object has a mass of 10 Kg. And it has a contact surface of 25 cm^2. How much pressure do the object apply to surface? Give your answer is Pascals.

    2. Relevant equations
    N

    3. The attempt at a solution
    So, I think I need to divide the mass with with the surface area to get kilogram-force per squared centimeter. Then I need to convert it into Pascals. But how do I convert it to Pascals? Is there a formula?
     
  2. jcsd
  3. Nov 2, 2014 #2
    The first step is to find the force. What is the force due to gravity? (F=?)

    one pascal is 1 N/m^2. so you need to use newtons and meters. This means convert cm^2 to m^2.

    Then you can use the definition of pressure (Pressure = Force/area), and your answer will be in pascals.
     
  4. Nov 2, 2014 #3
    Since Englsih isn't my first language so I had a bit of a hard time to understand, but I think I got it.
    F=m*g
    F=10kg*9,78=97,8N
    Then 25cm^2=0,4m^2
    97,8 N per 0,4m^2
    Pascal=97,8 N / 0,4m^2 = 244,5 Pa
    Pascal=244,5
    How is that?
     
  5. Nov 2, 2014 #4
    1 cm = 1/100 m, and 1 cm^2 = (1/100)^2 m^2 = 1/10000 m^2. therefore 25 cm^2 = ?
    hint: it is not 0.4m^2

    Otherwise your method looks correct
     
  6. Nov 2, 2014 #5
    Oh yea, it's 0,0025m^2 since it's squared. Thank you!
     
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