Dane:
[tex]m = 5kg\\T_1 = 30 \°C\\E = 84kJ=84000J\\Szukane:\\T_x = temp.koncowa[/tex]
[tex]E = m*c_w*\Delta T[/tex]
[tex]c_w = cieplo~wlasciwe~wody=4200\frac{J}{kg*\°C}[/tex]
[tex]\Delta T = T_x -T_1\\[/tex]
[tex]E = m*c_w*\Delta T=m*c_w*(T_x-T_1)=m*c_1*T_x-m*c_w*T_1[/tex]
[tex]T_x = \frac{E+m*c_w*T_1}{m*c_w} = \frac{84000J+5kg*4200\frac{J}{kg*\°C} }{5kg*4200\frac{J}{kg*\°C} } =34\° C[/tex]