The contents of the closed box in each of the following illustrations represent a system, and the arrows show the changes to the system during some process. The lengths of the arrows represent the relative magnitudes of q and w.
(a) Which of these processes is endothermic?
(b) For which of these processes, if any, is E 6 0?
(c) For which process, if any, does the system experience a net gain in internal energy? [Section 5.2]