Friction force from normal force
================================

The *friction* force is a tangential interaction between two objects, which impedes their relative
movement. In the phenomenological model of friction there is an empirical law stating that the
friction force is proportional to the normal force between the two objects.

**Links**

#. `Physics LibreTexts <https://phys.libretexts.org/Courses/Tuskegee_University/Algebra_Based_Physics_I/04%3A_Dynamics-_Force_and_Newton%27s_Laws_of_Motion/4.07%3A_Friction>`__.

.. py:currentmodule:: symplyphysics.classical_mechanics.dynamics.force.friction_force_from_normal_force

.. py:data:: friction_force

    The friction :attr:`~symplyphysics.symbols.classical_mechanics.force`.

Symbol:
    :code:`F_fr`

Latex:
    :math:`F_\text{fr}`

Dimension:
    :code:`force`


.. py:data:: friction_coefficient

    The :attr:`~symplyphysics.symbols.classical_mechanics.friction_coefficient` between the two objects.

Symbol:
    :code:`mu`

Latex:
    :math:`\mu`

Dimension:
    :code:`dimensionless`


.. py:data:: normal_force

    The normal reaction :attr:`~symplyphysics.symbols.classical_mechanics.force` from one object to another.

Symbol:
    :code:`N`

Latex:
    :math:`N`

Dimension:
    :code:`force`


.. py:data:: law

    :code:`F_fr = mu * N`


    Latex:
        .. math::
            F_\text{fr} = \mu N