<p>The position of the centre of mass of a uniform semi-circular wire of radius &#39;R&#39; placed in x-y plane with its centre at the origin and the line joining its ends as x-axis is given by&nbsp;<span class="equation">\(\begin{pmatrix}
0, \frac{xR}{\pi}
\end{pmatrix}\)</span>. Then, the value of <span class="equation">\(\begin{vmatrix}
x
\end{vmatrix}\)</span>&nbsp;is_______​​​​​​​​​​​​​​</p>