\textbf{186.} The velocity–position equation for a simple harmonic oscillator in SI units is $1 = V^2 + 250x^2 = \dfrac{25}{\pi^2}$. The oscillation frequency in hertz is?
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(1) $\dfrac{1}{2}$ \hfill (2) $1$ \hfill (3) $2$ \hfill (4) $5$
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