\begin{enumerate} \item (1) $\dfrac{10\pi}{2\pi} = \underline{5}$ [Hz] \item (2) $\dfrac{1}{5} = \underline{0.2}$ {\rm [s]} \item (3) $\dfrac{100\sqrt{2}}{\sqrt{2}} = \underline{100}$ {\rm [V]} \item (4) $\dfrac{2}{\pi}100\sqrt{2} = \underline{\dfrac{200\sqrt{2}}{\pi}}$ {\rm [V]} \end{enumerate}