Question

A wire of length l and radius r has a weight W and the Young's modulus of elasticity Y. It is suspended from a fixed point. Calculate the increase in length of wire produced due to its own weighty. (Fig).

Answer 1

The tension m the element of the wire

= mg/l × x

If dl is the increase in length of the element, then longitudinal strain = dl/dx.

Normal stress = mgx/l × 2/πr²