 Important formulas in kinematics define the velocity and acceleration of points in a moving body as they trace trajectories in three-dimensional space.This is particularly important for the center of mass of a body, which is used to derive equations of motion using either Newton's second law or Lagrange's equations.In order to define these formulas, the movement of a component "B" of a mechanical system is defined by the set of rotations [A(t)] and translations d(t) assembled into the homogeneous transformation [T(t)]=[A(t), d(t)].