Question

A rod AD, consisting of three segments AB, BC and CD joined together, is hanging vertically from a fixed support at A. The lengths of the segments are respectively 0.1 m, 0.2 m and 0.15 m. The crosssection of the rod is uniformly equal to 10–4 m2 . A weight of 10 kg is hung from D. Calculate the displacements of the points B, C and D using the data on Young’* moduli given below (neglect the weight of the rod).

YAB = 2.5 × 1010 N/m2 , YBC = 4.0 × 1010 N/m2 and YCD = 1.0 × 1010 N/m2 .

Answer 1

We know that Δl=Mgl/AY

For segment AB:

This is the displacement of B.

For segment BC:

Displacement of C

For segment CD :

Displacement of D