Đáp án:
$\left\{ \begin{align}
& {{m}_{d}}=3,12kg \\
& {{m}_{k}}=0,08kg \\
\end{align} \right.$
Giải thích các bước giải:
Ta có:
$\begin{align}
& m=3,2kg\Rightarrow P=3,2.10=32N \\
& m'=2,83kg\Rightarrow P-{{F}_{A}}=2,83.10=28,3N \\
\end{align}$
Lực đẩy:${{F}_{A}}=32-28,3=3,7N$
ta có:
$\left\{ \begin{align}
& {{m}_{d}}+{{m}_{k}}=3,2g \\
& {{d}_{nc}}.{{V}_{d}}+{{d}_{nc}}.{{V}_{k}}={{F}_{A}} \\
\end{align} \right.$
từ đó:
$\left\{ \begin{align}
& {{m}_{d}}+{{m}_{k}}=3,2g \\
& 10000.(\frac{{{m}_{d}}}{{{D}_{d}}}+\frac{{{m}_{k}}}{{{D}_{k}}})=3,7 \\
\end{align} \right.$
$\Leftrightarrow \left\{ \begin{align}
& {{m}_{d}}+{{m}_{k}}=3,2 \\
& \frac{{{m}_{d}}}{8700}+\frac{{{m}_{k}}}{7100}=3,{{7.10}^{-4}} \\
\end{align} \right.$
hàm lượng:
$\left\{ \begin{align}
& {{m}_{d}}=3,12kg \\
& {{m}_{k}}=0,08kg \\
\end{align} \right.$
