Answer Happy

Question #1 (27 marks] [35 minutes + 6 minutes for uploading A disc of a diameter D-100 mm, and thickness of 10 mm, has a surface temperature of 290°C and emissivity = =[0.X]. The disc is oriented horizontally and subjected to a cooling process inquiescent, ambient air and large surroundings for which T.-T-30°C. Neglect the heat transfer at the bottom and the side of the disc. a) Calculate the rate of heat transfer from the top surface? [14 marks) b) Will the disc cool faster or slower when it is oriented vertically, explain mathematically? 17 marks) c) Check the situation whether the convection is forced, natural or mixed convection in case the disc is subjected to moving air with a velocity 16 marks] of 3 m/s