The tension is resolved into horizontal copmponent T ` sin theta ` and vertical component `T cos theta `. ` T sin theta ` provides the centripetal force required for the horizontal circular motion
`therefore T sin theta = (mv^(2))/(r ) = m r omega ^(2)`
From the figure ` sin theta = (BC)/(OB) =(r )/(L )`
` therefore T. (r )/(L ) = m r omega ^(2) therefore T= Lomega ^(2)`
` omega^(2) = (T )/(mL ) = (324 )/((1)/(2)xx(1)/(2) )=324 xx4`
` therefore omega = sqrt(324xx4)=18 xx2=36 rad //s`