tóm tắc
\(m_{12}=664g\)
\(D_{12}=8.3g/cm^3\)
\(D_1=7300kg/m^3=7,3g/cm^3\)
\(D_2=11300kg/m^3=11,3g/cm^3\)
\(m_1=?g\)
\(m_2=?g\)
Bg:
GỌI m1 LÀ KL CỦA THIẾT
GỌI m2 LÀ KL CỦA CHÌ
TA CÓ \(m_{12}=m_1+m_2\)
\(v_{12}=v_1+v_2\)
\(\hept{\begin{cases}m_{12}=m_1+m_2\left(1\right)\\\frac{m_{12}}{D_{12}}=\frac{m_1+m_2}{D_1+D_2}\left(2\right)\end{cases}}\)
\(\Rightarrow\hept{\begin{cases}m_2=m_{12}-m_1\left(1\right)\\\frac{664}{8,3}=\frac{m_1}{D_1}+\frac{m_{12}-m_1}{D_2}\left(2\right)\end{cases}}\)
\(\Rightarrow\hept{\begin{cases}m_2=m_{12}-m_1\left(1\right)\\\frac{664}{8,3}=\frac{m_1}{7,3}+\frac{664-m_1}{11,3}\left(2\right)\end{cases}}\)
\(\Rightarrow\hept{\begin{cases}m_2=m_{12}-m_1\left(1\right)\\\frac{664}{8.3}=\frac{m_1}{7,3}+\frac{664-m_1}{11,3}\left(2\right)\end{cases}}\)
\(\Rightarrow\hept{\begin{cases}m_2=m_{12}-m_1\left(1\right)\\m_1=438\left(2\right)\end{cases}}\)
THAY (2) VÀO (1)
\(\Rightarrow\hept{\begin{cases}m_2=664-438=226g\\m_1=438g\end{cases}}\)
