A hot (800 K) and a cold (200 K) heat reservoirs are connected to each other by two identical aluminum bars in two different ways as shown in the figure. Compared to the left configuration, the rate of heat transfer in the right configuration is as high. (Complete the sentence.) three times four times twice one half one third one fourth

An insulated 40 ft^3 rigid tank contains air at 50 psia and 120°f. a valve connected to the tank is now opened, and air is allowed to escape until the pressure inside drops to 25 psia. the air temperature during this process is kept constant by an electric resistance heater placed in the tank. determine the electrical work done during this process.