(a)[1]
State the form of energy stored in the gas that is transferred by the heater.
(b(i))[3]
A metal screen around the burning gas is heated by the burning gas until it becomes red-hot. The hot metal screen heats the man standing underneath it. Describe how thermal energy in the red-hot metal screen is transferred to the man and how it warms him.
(b(ii))[2]
At the top of the heater there is a metal hood with a shiny lower surface. Explain why this makes the energy transfer from the metal screen more efficient.
(b(iii))[2]
The air temperature falls and the man puts on a black pullover. Explain one way in which wearing the black pullover helps to keep the man warm.