[tex]dane:\\m = 2 \ kg\\Q = 250 \ kJ = 250 \ 000 \ J\\T_2 = 45^{o}C\\c_{w} = 4200\frac{J}{kg\cdot^{o}C}\\szukane:\\T_1 = ?\\\\Rozwiazanie\\\\Q = m\cdot c_{w}\cdot(T_2 - T_1) \ \ /:(m\cdot c_{w})\\\\T_2 - T_1 = \frac{Q}{m\cdot c_{w}}\\\\-T_1 = \frac{Q}{m\cdot c_{w}}-T_2 \ \ /\cdot (-1)\\\\T_1 = T_2 - \frac{Q}{m\cdot c_{w}}[/tex]
[tex]T_1 = 45^{o}C - \frac{250000 \ J}{2 \ kg\cdot4200\frac{J}{kg\cdot^{o}C}}\\\\T_1= 45^{o}C - 29,76^{o}C\\\\\underline{T_1 = 15,24^{o}C}[/tex]
