Two parallel paths 35 m apart run east-west through the woods. Brooke jogs east on one path at 9 km/h, while Jamail walks west on the other path at 4 km/h. If they pass each other at time t = 0, How far apart are they 5 seconds later? How fast is the distance between them changing at that moment?

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 =