A copper wire is held at the two ends by rigid supports. At ${30}^0$ the wire is just taut with negligible tension. The speed of transverse waves in this wire at ${10}^{0}C$ is  $10\times Dm/s.$ Find the value of D(Take,  $Y_{cu}=1.3\times {10}^{11}Pa,$ ${\alpha }_{cu}1.7\times {10}^{-5}/{}^{0}C,{\rho }_{cu}=9000kg/m^3$)