A hydroelectric station supplies 3.6×1015J of electrical energy in one calendar year.
(i) Determine the mass of matter whose complete conversion into energy would yield the same amount of energy.
(ii) Express this mass in grams.
(iii) One tonne of coal has a mass of 1.0×103kg. Find the ratio of the mass calculated in part (ii) to the mass of one tonne of coal, and comment briefly on the result.