5. (20%) A solar collector made of aluminum with black coating is placed on the roof with a tilt degree of 45 with respect to the floor. The length of the solar collector is Im. The solar absorptivity of the absorber surface is 0.87 and the emissivity is 0.09. Assuming the solar irradiance to the ground is 800W/m, the air temperature is 25C and the effective sky temperature is 15C. It is measured that the surface temperature of the absorber is 75C. Determine 1) the natural convection heat transfer coefficient of the top absorber surface. 2) the net rate of solar energy delivered by the absorber plate to the water circulating behind it. Simi lr to 12 ay (55) Gl=800W/m T15C Al-To T25C T=75C Absorber plate 11111