When sugar is poured from the bag into the sugar bowl, the rubbing of the sugar grains creates a static electric charge that repels the grains and causes sugar to go flying out in all directions. If two sugar grains each acquire a charge of 7.10×10-11 C at a separation of 322 micrometers, with what force will they repel each other?

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 =