Ta có: \(\left\{{}\begin{matrix}Q_1=0,5\cdot880\cdot\left(100-30\right)=30800\left(J\right)\\Q_2=3\cdot4200\cdot\left(100-30\right)=882000\left(J\right)\end{matrix}\right.\)
\(\Rightarrow Q=Q_1+Q_2=30800+882000=912800\left(J\right)\)
TTĐ:
\(m_1=0,5kg\)
\(V_{nc}=3l\\ \Rightarrow m_2=3kg\)
\(c_1=880J/kg.K\)
\(c_2=4200J/kg.K\)
\(\Delta t_2=t_2-t_1=100-30=70^oC\)
\(\Rightarrow\Delta t_1=\Delta t_2=70^oC\)
__________________
\(Q=?\left(J\right)\)
Giải
Nhiệt lượng cần truyền cho ấm đun:
\(Q=Q_1+Q_2\)
\(\Leftrightarrow Q=m_1.c_1.\Delta t_1+m_2.c_2.\Delta t_2\)
\(\Leftrightarrow Q=0,5.880.70+3.4200.70\)
\(\Leftrightarrow Q=30800+882000\)
\(\Leftrightarrow Q=912800\left(J\right)\)