369672 Two blocks of masses \(1\;kg\) and \(2\;kg\) are connected by a metal wire going over a smooth pulley as shown. The breaking stress of the metal is \(\frac{{40}}{{3\pi }} \times {10^6}\;N/{m^2}\). If \(g = 10\;m/{s^2},\) then what should be minimum radius of the wire used if it is not to break?