a heat exchanger consists of a 1-shell pass and 6-tube pass configuration. water flows through the shell side with an inlet and outlet temperature of 340 k and 320 k, respectively. oil enters the tube side at 290 k and leaves at 315 k. the overall heat transfer coefficient is 1000 w/(m^2*k), and the overall heat transfer surface area is 25 m^2. determine the overall heat transfer rate