Question

Answer 1

Tóm tắt:
\(V=1l\Rightarrow m_1=1kg\)

\(m_2=0,5kg\)

\(c_1=4200J/kg.K\)

\(c_2=1800J/kg.K\)

\(t_1=25,5^oC\)

\(\Rightarrow\Delta t_1=t_1-t=25,5-t\left(^oC\right)\)

\(t_2=0^oC\)

\(\Delta t_2=t-t_2=t-0=t\left(^oC\right)\)

_______________

\(t=?^oC\)

Theo phương trình cân bằng nhiệt ta có:

\(Q_1=Q_2\)

\(\Leftrightarrow m_1c_1\left(25,5-t\right)=m_2c_2t\)

\(\Leftrightarrow1\cdot4200\cdot\left(25,5-t\right)=0,5\cdot1800\cdot t\)

\(\Leftrightarrow107100-4200t=900t\)

\(\Leftrightarrow4200t+900t=107100\)

\(\Leftrightarrow5100t=107100\)

\(\Leftrightarrow t=\dfrac{107100}{5100}=21^oC\)

Vậy nhiệt độ khi cân bằng là: \(21^oC\)