Diagram shows a shaft with brass segment A B of length 1800 millimeters which is connected to aluminum segment B C of length 800 millimeter using a flange at B and a torque T of 50 Newton meter is applied on C. The x axis is taken along the axis of the cylinders and the y axis is taken along the rigid support at A and perpendicular to the x axis. A positive internal torque T subscript 2 acts on B C towards B.

Note: Assume a positive internal torque.

Cut a FBD through segment (2) of the compound shaft.

Sum the moments acting around the x axis to find T2.

Mx=-T2+50 N-m=0T2=50 N-m