Chilled water enters a thin-shelled 4-cm-diameter, 200-mlong pipe at 7degreeC at a rate of 0.98 kg/s and leaves at 8degreeC. The pipe is exposed to ambient air at 30degreeC with a heat transfer coefficient of 9 W/m2 K. If the pipe is to be insulated with glass wool insulation (k = 0.05 W/m K) in order to decrease the temperature rise of water to 0.25degreeC, determine the required thickness of the insulation.