Diagram shows two vertical shafts A B marked 1 and C D marked 2 centered on the x and x prime axes respectively. A gear of 150 millimeter diameter is at A on shaft 1 at a height of 400 millimeters. A gear of 100 millimeter diameter is at C on shaft 2 at a height of 400 millimeters. Above the gear A a torque T is applied on shaft 1 in the counterclockwise direction. There is an inward twist on the shafts 1 and 2. The section on gear A is theta subscript A pointing in the counterclockwise direction. The section on gear C is theta subscript C pointing in the clockwise direction.

Since φA = φ1, compute the twist angle in shaft (1):