Linear displacement is angular displacement cross radius
========================================================

Assuming a body rotating around a fixed axis, the vector of its linear displacement can be expressed
as the cross product of the pseudovector of angular displacement and the radius vector of rotation.

**Conditions:**

#. The axis is fixed.
#. Angular displacement pseudovector and radius vector must be orthogonal to one another.

**Links:**

#. `Physics LibreTexts, formula 11.1.4 <https://phys.libretexts.org/Bookshelves/University_Physics/Book%3A_Introductory_Physics_-_Building_Models_to_Describe_Our_World_(Martin_Neary_Rinaldo_and_Woodman)/11%3A_Rotational_dynamics/11.01%3A_Rotational_kinematic_vectors>`__.

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



.. py:function:: displacement_law(angular_displacement_, rotation_radius_)

    Displacement vector.

    Law:
        :code:`s = cross(theta, r)`

    Latex:
        .. math::
            \vec s = \vec \theta \times \vec r

    :param angular_displacement\_: pseudovector of angular displacement parallel to axis of rotation

        Symbol: :code:`theta`
        
        Latex: :math:`\vec \theta`

        Dimension: *angle*

    :param rotation_radius\_: radius vector pointing away from the rotational axis and perpendicular to it

        Symbol: :code:`r`

        Latex: :math:`\vec r`

        Dimension: *length*

    :return: vector of linear displacement

        Symbol: :code:`s`

        Latex: :math:`\vec s`

        Dimension: *length*