[tex]dane:\\F = 0,5 \ kN = 0,5\cdot1000 \ N = 500 \ N\\s = 0,3 \ km = 0,3\cdot1000 \ m = 300 \ m\\szukane:\\W = ?\\\\W = F\cdot s\\\\W = 500 \ N\cdot300 \ m\\\\W = 150 \ 000 \ J = 150 \ kJ[/tex]