Câu hỏi 22

Ta có:

\(\begin{gathered}
\left\{ \begin{gathered}
{T_1} = 2\pi \sqrt {\frac{{{m_1}}}{k}} \hfill \\
{T_2} = 2\pi \sqrt {\frac{{{m_2}}}{k}} \hfill \\
T = 2\pi \sqrt {\frac{{{m_1} + {m_2}}}{k}} \hfill \\
\end{gathered} \right. \hfill \\
\Rightarrow T = \sqrt {T_1^2 + T_2^2} = \sqrt {{{0,5}^2} + {1^2}} = 1,12s \hfill \\
\end{gathered} \)

Chọn C.