3. For a collector having the following characteristics: Overall loss coefficient = 6.9 W/mc Tube spacing = 120 mm Tube outside diameter = 15 mm Tube inside diameter = 13.5 mm Plate thickness = 0.4 mm Plate material = Steel, k = 47.6 W/mC Heat transfer coefficient inside the tubes = 320 W/m Collector area = 4 m Flow rate = 0.06 kg/s = 0.8 Global solar radiation for 1hr = 2.88 MJ/m Collector temperature difference = 5C Ignoring the bond resistance, calculate: a. Fin efficiency b. Collector efficiency factor c. Useful energy d. Overall efficiency e. How do the values of overall efficiency of steel compare against copper (F' = 0.858) and aluminum (F' = 0.881)?