1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Tensile stress

  1. Apr 28, 2007 #1
    1. The problem statement, all variables and given/known data
    A load of 172 kg is supported by a wire of length 2.07m and cross-sectional area .143cm^2. The wire is stretched by 0.149 cm. Find tensile stress, strain, and Young's modulus.


    2. Relevant equations

    stress= F/A
    strain= ∆L/L
    E= stress/strain

    3. The attempt at a solution

    1685.6 N /.00143 m^2 = 1.17874e6 N/m^2 <---this one I need help with

    .00149 m / 2.07 m = .00072 <--- I know this one is right

    1.17874e6 N/m^2 / .00072 = 1.63758e9 N/m^2
     
  2. jcsd
  3. Apr 28, 2007 #2

    Pyrrhus

    User Avatar
    Homework Helper

    0.143 cm2 to m2 is wrong. Remember it'll be 10^-4 m2.
     
  4. Apr 28, 2007 #3

    Doc Al

    User Avatar

    Staff: Mentor

    Careful with units: 1 cm^2 = (0.01m)^2 = 0.0001 m^2
     
  5. Apr 28, 2007 #4
    so the answer to the stress is 1685.6 N / .0000143 m^2 = 1.17874e8

    which makes E = 1.63714e11
     
    Last edited: Apr 28, 2007
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?