A student was asked to investigate the heat loss from two metal cans, L and M. The cans were identical except for the outside colour.

A student had read about a glacier that had been covered in insulating material. The idea was to slow down the rate at which the glacier melts in the summer. She investigated this idea using the apparatus shown in the diagram.

(a) In winter, energy is transferred from the warm air inside a house to the air outside. (i) What effect will the energy transferred from the house have on the air outside? (1 mark)