Classical addition of velocities ================================ The *law of classical addition of velocities*, usually attributed to Galileo and called the *Galilean law of velocity addition*, states that the velocity of a body in an inertial reference frame :math:`A` can be found as a sum of its velocity in another inertial reference frame :math:`B` and the velocity of frame :math:`B` relative to frame :math:`A`. **Conditions:** #. Velocity vectors must be collinear. #. Space and time are absolute. #. Applicable to inertial reference frames. **Links:** #. `Wikipedia, vector counterpart of this law <https://en.wikipedia.org/wiki/Velocity-addition_formula#Galilean_relativity>`__. .. py:currentmodule:: symplyphysics.laws.kinematics.classical_addition_of_velocities .. py:data:: body_speed_in_first_frame :attr:`~symplyphysics.symbols.classical_mechanics.speed` of the body in frame :math:`A`. Symbol: :code:`v_OA` Latex: :math:`v_{OA}` Dimension: :code:`velocity` .. py:data:: body_speed_in_second_frame :attr:`~symplyphysics.symbols.classical_mechanics.speed` of the body in frame :math:`B`. Symbol: :code:`v_OB` Latex: :math:`v_{OB}` Dimension: :code:`velocity` .. py:data:: second_frame_speed_in_first_frame :attr:`~symplyphysics.symbols.classical_mechanics.speed` of frame :math:`B` relative to frame :math:`A`. Symbol: :code:`v_BA` Latex: :math:`v_{BA}` Dimension: :code:`velocity` .. py:data:: law :code:`v_OA = v_OB + v_BA` Latex: .. math:: v_{OA} = v_{OB} + v_{BA}