[tex]dane:\\P = 7,5 \ kW\\t = 6 \ h\\1 \ kWh = 3 \ 600 \ 000 \ J\\szukane:\\W = ?\\\\P = \frac{W}{t} \ \ /\cdot t\\\\W = P\cdot t\\\\W = 7,5 \ kW\cdot6 \ h = 45 \ kWh\\\\45 \ kWh = 45\cdot3 \ 600 \ 000 \ J = 162 \ 000 \ 000 \ J = 162 \ 000 \ kJ =162 \ MJ\\\\\boxed{W = 45 \ kWh = 162 \ MJ} \\\\1 \ kJ = 1000 \ J\\1 \ MJ = 1 \ 000 \ 000 \ J[/tex]
