Center of mass for a system of particles
========================================

The center of mass (com) of a system of particles is a unique point at any given time where
the sum of weighted relative positions of the distributed mass is zero.

**Links:**

#. `Wikipedia, second formula <https://en.wikipedia.org/wiki/Center_of_mass#A_system_of_particles>`__.

.. py:currentmodule:: symplyphysics.laws.kinematics.vector.center_of_mass_for_system_of_particles



.. py:function:: center_of_mass_law(masses_, position_vectors_)

    Vector of the center of mass from masses and position vectors.

    Law:
        :code:`r_com = Sum(m_i * r_i, i) / Sum(m_i, i)`

    Latex:
        .. math::
            {\vec r}_\text{com} = \frac{\sum_i m_i {\vec r}_i}{\sum_i m_i}

    :param masses\_: sequence of masses of individual parts

        Symbol: :code:`m_i`

        Latex: :math:`m_i`

        Dimension: *mass*

    :param position_vectors\_: sequence of position vectors of individual parts

        Symbol: :code:`r_i`

        Latex: :math:`{\vec r}_i`

        Dimension: *length*

    :return: vector of the center of mass

        Symbol: :code:`r_com`

        Latex: :math:`{\vec r}_\text{com}`

        Dimension: *length*