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jdawg
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Homework Statement
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=40cm. Find (a) the x coordinate (b) the y coordinate, and (c) the z coordinate of the center of mass of the box.
Ok, so my professor already worked this problem for us, but I have no clue what she did.
Homework Equations
The Attempt at a Solution
L=40 cm=0.4 m
Then she divided that by two for some reason?
Front and Back center of mass: (0.2, 0.2, 0.2)
Right and Left center of mass: (0.2, 0.2, 0.2)
Top and Bottom (top is missing): (0.2 ,0.2 , 0)
xcm=[itex]\frac{1}{5m}[/itex](2m(0.2)+2m(0.2)+m(0.2))=0.2m
ycm=[itex]\frac{1}{5m}[/itex](2m(0.2)+2m(0.2)+m(0.2))=0.2m
zcm=[itex]\frac{1}{5m}[/itex](2m(0.2)+2m(0.2)+m(0))=0.16m
I am so confused! Can someone please explain to me what she did? Is there a formula that she used? I looked in my book and the only one I found needed the mass to use it.