The image shows the relative positions of Earth and the Sun for each of the four seasons. Earth travels in an elliptical orbit and is about two million miles closer to the Sun in the winter than in the summer.(DOK 2)

Consider a spherical container of inner radius , outer radius r2, and thermal conductivity k. express the boundary condition on the inner surface of the container for steady one-dimensional conduction for the following cases: (a) specified temperature of 50°c, (b) specified heat flux of 30 w/m2 toward the center, (c) convection to a medium at t with a heat transfer coefficient of h