Question

# Figure 6 shows a thermal solar panel to be used on the roof of a house.Water is heated by solar radiation as it flows through a pipe in the solar panel. Not all of the solar radiation incident on the Earth's upper atmosphere reaches the Earth's surface. The proportion R of solar radiation incident on the Earth's surface is given by: R=\frac{\text { solar power per } \mathrm{m}^{2} \text { incident on the Earth's surface }}{\text { solar power per } \mathrm{m}^{2} \text { incident on the Earth's upper atmosphere }} Solar radiation is incident normally on the surface of the solar panel with a power of 2.2 x 10³ W. Calculate R. total power output of Sun = 3.85 x 1026 W distance between Earth and Sun = 1.50 × 10¹¹ mof th area of the upper surface of the panel = 5.5 m² The rate of flow of water through the panel is 45 g s¹.TH of water through the panel is 45 g s '.The water enters the panel at a temperature of 15 °C and absorbs energy from the panel at a rate of 1.7 kW.bon Calculate the temperature of the water as it leaves the panel. \text { specific heat capacity of water }=4200 \mathrm{~J} \mathrm{~kg}^{-1} \mathrm{~K}^{-1}  Fig: 1  Fig: 2  Fig: 3  Fig: 4  Fig: 5  Fig: 6  Fig: 7  Fig: 8  Fig: 9  Fig: 10  Fig: 11  Fig: 12  Fig: 13  Fig: 14