Question $2.$ Two journal bearings support the $80-mm$ diameter shaft CDE, while the $60-mm$ shaft $BA$ is fixed at A$.$ The shafts are made of A$-36$ steel.

a$.$ If the angle of twist at gears $C$ and $E$ is required to be $0\mathrm{.}04$ rad, determine the magnitudes of the torques $T_1.$

b$.$ If $T_1=2kNm,$ determine the twist angle of gears D and E $.$