A steel wire of length 2 m and cross sectional area `2 mm^2` is fixed at one end and stretched by suspending a block of mass 2 kg on the surface of the moon. If the Young's modulus of steel is `2 xx 10^11 N m^(-2)` find the increase in the length of the steel wire. (g on the moon = 1/6 of the g on the earth)

Explanation

`L= 2 m, A= 2 mm^2 = 2 xx 10^(-6) m^2`,
M = 2 kg: g on the moon = `g/6 = (9.8)/(6) ms^(-2)`
`Y = 2 xx 10^11 (N)/(m^2) , e = ?`
The increase in length
` e = (FL)/(AY) = (MgL)/(AY) = (2 xx 9.8 xx 2)/(6 xx 2 xx 10^(-6) xx 2 xx 10^11)`
` = 1.633 xx 10^(-5) m`