Halliday, Resnick & Walker — Center of Mass and Linear Momentum: Problem 6

6 Figure 9-28 shows a cubical box that has been constructed from uniform metal plate of negligible thickness. The box is open at the top and has edge length $L = 50\text{ cm}$. Find (a) the $x$ coordinate, (b) the $y$ coordinate, and (c) the $z$ coordinate of the center of mass of the box.