A metallic sphere with a diameter 60-mm is hanged in the air with a temperature Tg = 30C and a flow speed around 10 m/s. A laser beam is applied to heat and to oxidize the surface of the sphere. To properly oxidize the sphere, the surface temperature of the sphere should be equal or higher than 1000C. Sphere Tg=30C V=10 m/s Laser irradiation G Wavelength = 0.5 m (a) Determine the minimum laser irradiation G required to support the oxidation of the metallic sphere if the sphere is a blackbody (8 pt.) (b) Determine the total emissivity and the total absorptivity of the sphere if the sphere surface is diffuse with the following emissivity spectrum. (9 pt.) 1 3 () (c) Determine the minimum laser irradiation G required to support the oxidation of the metallic sphere if the sphere has a diffuse surface with the above emissivity spectrum. (10 pt.) (d) Determine the temperature at the center of the sphere under the steady-state condition. (5 pt.)