Two people are holding up the ends of a 4.25-kg wooden plank. a 6.00-kg box sits in the center of the plank. what forces do the people exert on the plank? hint: the forces of the people must equal the forces acting on the box and the plank.

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 =