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How to calculate density from specific weight in imperial units

  1. Jan 31, 2010 #1
    1. The problem statement, all variables and given/known data
    alright so i have to find the density of a clay unit. im given a specific weight of the clay as 120 b/ft^3, the gravity constant as 32.17 ft/s^2. i need to find the density of the clay, i have no problem arranging the equation below to solve for density but im not used to working in imperial units and im not allowed to switch to metric. ive attempted it below and just wondering if i did it correctly

    2. Relevant equations
    specific weight= gravity x density

    3. The attempt at a solution
    density= specific weight/gravity
    = 120 lb/ft^3/32.17 ft/s^2
    = 3.73 lb/ ft^2 s^2

    so are my units correct?
  2. jcsd
  3. Jan 31, 2010 #2


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    Homework Helper

    No, your units aren't correct. Check your work.
  4. Jan 31, 2010 #3
    could you give me a hint?
    to me it seems correct, im dividing lb/ft^3 by ft/s^2. so the only thing that would cancel is the ft in the numerator and denomanator.

    i understand that in metric it kg/m^3, but ive never used imperial. would it be lb/ft^3? how would the units cancel out?
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