8. A wall 0.1m thick is made of brick with k = 0.5 W/m K. The air adjacent to one side has a temperature of 30C, and that on the other 0C. Calculate the heat flux through the wall if there is a heat transfer coefficient of 20 W/m2K acting on both sides. 600 W/m2 120 W/m2 150 W/m2 . 100 W 100 W/m2 . 9. Which provides the highest thermal resistance in Question 8? the conduction path the two convection coefficients conduction and convection give equal thermal resistance . there is zero thermal resistance the thermal resistance is infinite 10. What is the appropriate form of the conduction equation for steady-state radial conduction in a pipe wall? aT 1 T aT aT a) b) dr a t dr =0; c)- dT Ox -=0; d)Q=hAAT; e) =0 dr dr a pipe wall? 11. The temperature, T at radius r within a pipe of inner radius rl and outer radius ro, where the temperatures are TI and TO, respectively, is given by: a) T-Tr T-T r/r = b) = T-T log, r/rc). T-T T-T_loger/r = logr T-T r/r T-T r/r T-T d) = ; e). I -=1-e T-T logr T-T 12. The British Thermal Unit (Btu) is a measure of energy in the British or Imperial system of units. Given that, you should be able to deduce the correct units for thermal conductivity in the Imperial system. What is it? Btu/ft F Btu/ ft hr F Btu/ft2 hr F Btu/hr F Btu