A large window measures 2.0 m by 3.0 m. At what rate will heat be conducted through the window when the room temperature is and the outside temperature is if
(a) The window consists of a single pane of glass 4.0 mm thick and
(b) The window instead has a double pane of glass (a “thermopane”), in which each pane is 2.0 mm thick, with an intervening air space of 1.0 mm? (Assume that there is a constant temperature difference and consider conduction only.)