Physics 5054 · Question 1[10 marks]
A rooftop solar collector panel of surface area 2.5 m² receives solar radiation at a rate of 800 W m⁻². Water of mass 120 kg flows through copper pipes bonded to the black absorber plate.
(a)[2]
Calculate the total solar power incident on the panel.
(b)[3]
Calculate the thermal energy required to heat 120 kg of water from 15 °C to 55 °C. (Specific heat capacity of water c = 4200 J kg⁻¹ °)
(c)[3]
If the panel heats this water in 3.0 hours (10,800 s), calculate the useful output power and the overall efficiency of the solar heating system.
(d)[2]
Explain two design features of the panel that maximize energy absorption and minimize heat loss.