The diameter of a brass rod is 4 mm and Young's modulus of brass is 9 xx 10 ^(9) Nm ^(-2),What will be the force required to stretch by 0.1% of its length ?

The diameter of a brass rod is 4 mm and Young's modulus of brass is 9

1.	The diameter of a brass rod is 4 mm and Young's modulus of brass is 9 xx 10 ^(9) Nm ^(-2),What will be the force required to stretch by 0.1% of its length ?
Answer» `36pi N` `36 N` `36 pi xx 10 ^(5) N` `144 pi xx 10 ^(3)N` Solution :Longitudinal strain `(Delta L )/(l) = (0.1)/(100) =1 xx 10 ^(-3)` Now `Y= (F)/(A) xx (l)/(Delta l )` `=F = YA xx (Deltal )/(l)` `= 9 xx 10 ^(9) xx pi R ^(2) xx 1 xx 10 ^(-3)` `= 0 xx 10 ^(9) xx pi xx(2 xx 10 ^(-3)) ^(2) xx 1 xx 10 ^(-3)` `= 36 pi xx 10 ^(0)` `= 36 pi N`