Áp dụng phương trình cân bằng nhiệt:
\(Q_1+Q_2=0\)
\(\Leftrightarrow m_1.C_n.\left(t_1-t_0\right)+m_2.C_n.\left(t_2-t_0\right)=0\)
\(\Leftrightarrow0,4.4200\left(16-t_0\right)+0,2.4200\left(70-t_0\right)=0\)
\(\Leftrightarrow6,4-0,4t_0+14-0,2t_0=0\)
\(\Leftrightarrow0,6t_0=20,4\)
\(\Leftrightarrow t_0=34^oC\)