[tex]Dane:\\m_1 = 66 \ kg\\t_1 = 18^{o}C\\m_2 = 1,5 \ kg\\t_2 = 48^{o}C\\Szukane:\\t_{k}=?\\\\Rozwiazanie\\\\Q_{pobrane} = Q_{oddane}\\\\m_1c(t_{k}-t_1) = m_2c(t_2-t_{k}) \ \ |:c\\\\m_1(t_{k}-t_1) = m_2(t_2-t_{k})\\\\m_1t_{k}-m_1t_1 = m_2t_2-m_2t_{k}\\\\m_1t_{k}+m_2t_{k} = m_1t_1+m_2t_2}\\\\t_{k}(m_1+m_2) = m_1t_1 + m_2t_2 \ \ |:(m_1+m_2)\\\\t_{k} = \frac{m_1t_1+m_2t_2}{m_1+m_2}\\\\t_{k} = \frac{66 \ kg\cdot18^{o}C +1,5 \ kg\cdot48^{o}C}{66 \ kg+1,5 \ kg}\\\\t_{k}=18,(6)^{o}C \approx18,7^{o}C[/tex]
