he figure shows a compound axial member consisting of a larger cylindrical segment A B which is marked 1 having a length of 1800 millimeters flanged to another cylindrical segment B C which is marked 2 having a length of 800 millimeters. Segment 1 is fixed to a wall at the point A. The x axis is taken along the common axis of the two cylindrical members and the y axis is taken perpendicular to the x axis along the wall. The tension load at the free end of segment 2 is P which equals 50 kilo newtons oriented in the positive x direction.

A load of P=50 kN is applied to a compound axial member. Segment (1) is a 20-mm-diameter solid brass (E=100 GPa) rod. Segment (2) is a solid aluminum (E=70 GPa) rod.

Determine the minimum diameter of the aluminum segment if the axial displacement of C relative to support A must not exceed 5 mm.