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`