A stone of 0.5 kg mass is attached to one end of a 0.8 m long aluminium wire of 0.7 mm diameter and suspended vertically . The stone is now rotated in a horizontal plane at a rate such that the wire makes an angle of `85^@` with the vertical . find the increase in the length of the wire . The Young's modulus of aluminium = `7 xx 10^(10) Nm^(-2)`, `sin 85^@`= 0.9962 , cos `85^@` = 0.0872