How does the force of gravity between two bodies change when the distance between them doubles? 1. unable to determine; the mass is needed. 2. doubles 3. halves 4. quadruples 5. remains the same 6. drops to one quarter of its original value?

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 =