In an action-reaction pair a. action force is exerted first

b. action force and the reaction force are equal in magnitude and act in the same direction.

c. action force and the reaction force are contact forces only.

d. action force and the reaction force act on two different objects.

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 =