This lecture covers the calculation of the moment of inertia of a thin disk, the collision between two bodies, the transfer theorem, and the concept of the center of mass in solid mechanics. It also delves into the kinematics of a solid, including the composition of rotations, the concept of an inextensible solid, and the determination of the center of mass. The lecture concludes with a discussion on the relationship between absolute and relative velocities and accelerations in a solid, emphasizing the importance of understanding these concepts in the context of mechanics.