7-46

$${1\, \mathrm{kilovatt-tund} = 1\, \mathrm{kW} \cdot \mathrm{h} = (10^3\, \mathrm{W})(3600\, \mathrm{s}) = 3,60 \times 10^6\, \mathrm{J} = 3,60\, \mathrm{MJ}}$$