The impedance of a material is Z=rhoc, the density times the speed of sound. Consider the following information: Zlung=0.18×106kg s/m2. Zfat=1.34×106kg s/m2. What fraction of the incident intensity of a sound pulse will be reflected when sound travels from fat into lung? Express your answer in percent.

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 =