The speed of a transverse wave passing through a string of length 50 cm and mass 10 g is 60 ms–1 . The area of cross-section of the wire is 2.0 mm2 and its Young's modulus is 1.2 x 1011 Nm–2 . The extension of the wire over its natural length due to its tension will be x × 10–5 m. The value of x is_____.