A steel wire of length 4 m and diameter 5 mm is stretched by kg-wt. Find the increase in its length if the Young's modulus of steel wire is `2.4 xx 10^(12) dyn e cm^(-2)`

Answer

`4.1 xx 10^(-3) cm`

Explanation

Here,` l = 4m = 400 cm, r = (5//2)mm = (5//20)cm , Y = 2.4 xx 10^(12) dyn e cm^(-2), F = 5kg wt = 5000 g wt = 5000 g wt = 5000 xx 980 dyn e`
`Delta l = (Fl)/(pi r^2 Y) = ((5000 xx 980)xx400)/(3.14 xx (5//20)^2xx10^(12))`
= 0.0041 cm