A mild steel wire of length 1.0 m and cross-sectional area 0.50 × 10–2 cm2 is stretched, well within its elastic limit, horizontally between two pillars. A mass of 100 g is suspended from the mid-point of the wire. Calculate the depression at the midpoint.

Question

anonymous · Answer

Young's mod for steel is 2*(10)^11 N/m^2
I have the solution to this question but I want to know why young's modulus and its concept is used and not shearing concept and modulus.

roadjester · Answer

The shear modulus is used for "diagonal" movement. For example a book. When you slide a book by pressing down on a table, the last page of the book is still touching the table but the top is still sliding. That is the shear modulus. In this problem however, it is a wire which is not "thick" enough to apply the shear modulus.

anonymous · Answer

but shear modulus IS used for a spring right? so why not here?

vincent-lyon.fr · Answer

Because in the spring, the wire is coiled and so the deformation is a sideways one.