Question - A plane wall made of material of density 7800 kg/m3, thermal conductivity 45 W/mK and specific heat 465 J/kgK is 0.12 m thick. After it was heated to a uniform temperature of 310°C, the wall is exposed to convection on both sides to surroundings at 30^oC with a convective heat transfer coefficient of 450 W/m2K. Determine the temperature after 8 minutes at

(i) mid plane

(ii) 0.03 m from centre plane and

(iii) 0.054 m from centre plane and

(iv) at the surface.

Also calculate (i) the heat flow out during this period for 1 m2 area on one side and (ii) The instantaneous flow rate at the surface.