Odpowiedź :
[tex]Dane:\\m = 500 \ g = 0,5 \ kg\\T_1 = 10^{o}C\\T_2 = 30^{o}C\\\Delta T = T_2 - T_1 = 30^{o}C - 10^{o}C = 20^{o}C\\c = 2100\frac{J}{kg\cdot ^{o}C}\\Szukane:\\Q = ?\\\\Q = m\cdot c\cdot \Delta T\\\\Q = 0,5 \ kg\cdot2100\frac{J}{kg\cdot^{o}C}\cdot20^{o}C\\\\\boxed{Q = 21 \ 000 \ J = 21\ \ kJ}\\\\(1 \ kJ = 1000 \ J)[/tex]