Figure shown 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 `40 cm`. The z co-ordinate of the centre of mass of the box in cm, is.
.

Options

A. 12
B. 16
C. 20
D. 22

Answer

B

Explanation

(b) If `m` is mass of one plate, then
`Z_(cm) =(m.20 +m.20+ m.20 +m.20 +m.0)/(5 m) = 16 cm`.