**Question **# a. If the convection coefficient inside the furnace is hf= 100 W/m². K, find the time required forcenterline temperature of steel shaft to reach 1200 K.Also, find the amount of heat transferredduring the process. b. The steel shaft at 1200 K is taken out of furnace and placed in air at 300 K. If it takes 2.5 hrs for the centerline temperature of steel to reach 450 K, find the convection coefficient. Also, find the amount of heat transferred during the process. Assume lumped heat capacity system. 1. A 0.1-m diameter steel (k= 50 W/m. K,p= 8000 kg/m³,temperature 300 K is placed in a furnace where the furnace gases at 1500 K are used for heat treatment.',c = 500 J/kg. K) shaft with initial