Plan the Solution  
scene 2 of 11
Diagram shows an aluminum shaft A B with a support at A, marked 1 of length 2,000 millimeters and a brass shaft B C with a support at C, marked 2 of length 800 millimeters with a flange in between at B. The shafts are centered on the x axis. A torque T is applied at B.

The procedure to solve this problem
can be outlined as:

• Equilibrium
Draw a free-body diagram (FBD) of flange B to determine the relationship of internal torques T1 and T2 to the applied torque T.

• Geometry of deformation
From the angles of rotation at A, B, and C, we will deduce the relationship between the twist angles in shafts (1) and (2).

• Torque-twist relationships
The relationship between internal torque and angle of twist will be expressed for each shaft.

• Compute torques in (1) & (2)
We will combine the torque-twist relationships with the geometry of deformation relationship to compute the internal torques T1 and T2.

Answer the questions
Once T1 and T2 are computed, the values required for this problem can be determined.