# Heat is generated in a 8 cm diameter spherical radioactive material whose thermal conductivity is 25 W/m.°C uniformly at a rate of 15×10^6 W/m³.

Heat is generated in a 8 cm diameter spherical radioactive material whose thermal conductivity is 25 W/m.°C uniformly at a rate of 15×10^6 W/m³. If the surface temperature of the material is measured to be 120°C, What is the center temperature of the material during steady operation?