By considering the size and shape of the fermi surface in relation to the brillouin zones associated with a simple cubic metal lattice, show why it is that a divalent metal can, in practice, conduct electricity. in what qualitative way does the strength of the lattice potential affect this behaviour? (you should use sketches to illustrate your answers.

Electric field of the earth. the earth has a net electric charge that causes a field at points near its surface equal to 150 n> c and directed in toward the center of the earth. (a) what magnitude and sign of charge would a 60-kg human have to acquire to overcome his or her weight by the force exerted by the earth’s electric field? (b) what would be the force of repulsion between two people each with the charge calculated in part (a) and separated by a distance of 100 m? is use of the earth’s electric field a feasible means of flight? why or why not?