2.A cylindrical heated rod protrudes from a spaceship. The rod loses heat to outer space by radiation only.Assuming that the emissivity of the rod is Є and that none of the radiation leaving the rod is reflected back, derive the differential equation for the steady-state temperature distribution in the rod , Aso set up the boundary conditions which the differential equation must satisfy .The length of the rod is L,its cross sectional area is A , its permeter is P , its radius is R ( L>>R) , and its base temperature is constant at To .Assume that outer space is a black body at 0°C.You are not asked to solve to differential equation.