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!

The z coordinate of the center of mass of the box

  1. Feb 21, 2008 #1
    1. The problem statement, all variables and given/known data
    A cubical box has been constructed from uniform metal plate of negligible thickness. The box is open at the top and has edge length L = 97 cm. Find (a) the x coordinate, (b) the y coordinate, and (c) the z coordinate of the center of mass of the box.

    2. Relevant equations

    3. The attempt at a solution
    I could not figure out what to do with a three dimensional object since we are not given a mass.
  2. jcsd
  3. Feb 22, 2008 #2

    Shooting Star

    User Avatar
    Homework Helper

    Assume some [itex]\sigma[/itex] as the two dimensional mass density, that is, mass per unit area of the faces. Multiplying [itex]\sigma[/itex] by area, you'll get the mass. I think you know where the CM of a rectangle is. Now, apply the formula you know.
  4. Feb 22, 2008 #3


    User Avatar
    Homework Helper

    If you assume that the mass of one side is M then the com of the four upright sides will correspond to a "particle" of mass 4M in the middle of the box. You now need to combine this with a "particle" of mass M in the middle of the bottom to get the overall com.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: The z coordinate of the center of mass of the box