Kinematics Chapter 10: General motion of a rigid bod §1 10-1 Composition of rotations about two parallel axes Composition problem of rotations about parallel axes is often encountered in mechanical engineering. For instance, the planet gear wheel in a planet gear mechanism has plane motion. In previous study, we dealt with a plane motion of a planet gear by decomposing it into a translation and a rotation. However, it is more convenient to view the plane motion of a planet gear as a composition of two rotations.5 Chapter 10: General motion of a rigid body §10-1 Composition of rotations about two parallel axes Composition problem of rotations about parallel axes is often encountered in mechanical engineering. For instance, the planet gear wheel in a planet gear mechanism has plane motion. In previous study, we dealt with a plane motion of a planet gear by decomposing it into a translation and a rotation. However, it is more convenient to view the plane motion of a planet gear as a composition of two rotations