transfer processes of heat

1.Water from the storage tank is pumped through the solar panel.In the solar panel,the water passes through copper pipes that are painted black.The water is then returned to the storage tank.

ai)Explain why the pipes in the solar panel are painter black.

ii)Plastic pipes are cheaper than copper pipes.Explain why coppe pipes are used in the panel rather than plastic ones.

b)Write down one advantage and one disadvantage of using solar panels rather than gas to heat a house.

2a)The sunu transfers energy to the Earth.Before reaching the Earth only one process is involved in this transfer.State the process and give a reason for your answer.

b)This marathon runner has been running for more than 23miles.He is very hot and sweaty.
Sweating helps the runner to lose energy.Use your ideas about energy transfer to explain how this happens.

c)After the race,the runner is given a shiny foil blanket.This stops him cooling down too quickly.Use your ideas about energy transfer to explain two ways in which this happens.