Four particles of mass 1kg , 2kg , 3kg and 4kg are placed at the four vertices A , B , C and D of square of side 1m . Find the position of centre of mass of the particle.

Appreciated if self - explained~ ☘

Consider the growth of a 20-nm-diameter silicon nanowire onto a silicon wafer. the temperature of the wafer surface is maintained at 2400 k. assume the thermal conductivity of the silicon nanowire is 20 wm-1k-1 and all its surfaces including the tip are subjected to convection heat transfer with the coefficient h = 1×105 wm-2k-1 and t∞ = 8000 k. when the nanowire grows to l = 300 nm, what is the temperature of the nanowire tip (t (x =