Two identical particles of mass \( 1 \, \text{kg} \) each go round a circle of radius \( R \), under the action of their mutual gravitational attraction. The angular speed of each particle is:
\( \frac{1}{2R}\sqrt{\frac{1}{G}} \)
\( \sqrt{\frac{2G}{R^3}} \)
\( \frac{1}{2}\sqrt{\frac{G}{R^3}} \)
\( \sqrt{\frac{G}{2R^3}} \)