How many kilograms of water can be evaporated from a 1 m2 surface of water in a lake on a hot, clear summer day, if it is assumed that the limiting factor is the Sun's heat of 1800 Js−1m−2 for an 8-hour day? Assume that the air and water temperatures remain constant at 40∘C.

Which process does not require the presence of a physical substance in order to transfer heat? air in the atmosphere is heated by the ground. this warm air then rises, and cooler air falls. this is an example of what type of process? how is conduction different from radiation?