An air heater for an industrial application consists of an insulated, concentric tube annulus, for which air flows through a thin-walled inner tube. Saturated steam flows through the outer annulus, and condensation of the steam maintains a uniform temperature Ts on the tube surface. Consider conditions for which air enters a 50-mmdiameter tube at a pressure of 5 atm, a temperature of Tm,i 17 C, and a flow rate of , while saturated steam at 2.455 bars condenses on the outer surface of the tube. If the length of the annulus is L 5 m, what are the outlet temperature Tm,o and pressure po of the air? What is the mass rate at which condensate leaves the annulus?
4) We saw in class that an electron wavefunction can actually extend through a classically forbidden region of space (potential barrier) where the potential energy is higher than the electron’s kinetic energy. This process is called quantum mechanical tunneling. In the lecture notes, we plotted th e tunneling probability for an electron as a function of barrier height and width. Using this plot, (a.) what will the probability be of finding an electron on the other side of a potential barrier 1 nm wide if its potential height is 0.5 eV higher than the kinetic energy of the electron (b.) What is the probability if the barrier is the same height as before but 5 nm wide (c.) What is the tunneling probability for a 2 nm wide barrier if the difference between electron