A 20 cm diameter copper ball object is to be heated from 100"C to an average temperature of 150"C in 30 minutes. Take the average density and specific heat of copper in this temperature range to be 8650 kg/m3 and 0.395 kJ/kgC respectively. What would be the mass of the object in kg? a. 299.92 O b. 289.86 O c. 89.32 O d. 36.23 O e. 37.49 A 5cmradius and 2m long stainless-steel rod at a surface temperature of 77°C is freely suspended in the middle of room which is at 22°C. If the air side convective heat transfer co-efficient is 68.14 W/mK, the emissivity of the rod is 0.8, determine the rate of heat transfer from the rod to room by convection O a. 1177.37 W O b. 1192.09 W O c. 11.921 kW O d. 2413.63 W