Imagine you are a teacher of a science class. a student brings in a newspaper article that claims the world will run out of energy by the year 2050 because all the oil will be pumped out of the planet. the student is confused because she has learned in your class that energy can never be created or destroyed. how would you explain to her what "running out of energy" means in the article?

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 =