Quantities
==========

Physical quantities can often be categorized as being either *extensive* or *intensive*, according to
how the property changes when the size or extent of the system changes.

**Intensive quantity**
    A quantity whose magnitude is independent of the size of the system.

**Extensive quantity**
    A quantity whose magnitude scales linearly with the size of the system,
    i.e. it is additive with respect to its subsystems.

.. py:currentmodule:: symplyphysics.laws.quantities

**Contents:**

.. toctree::
    :maxdepth: 4


    laws.quantities.fractional_change_is_change_over_initial_value
    laws.quantities.quantity_is_areal_density_times_area
    laws.quantities.quantity_is_linear_density_times_length
    laws.quantities.quantity_is_molar_quantity_times_amount_of_substance
    laws.quantities.quantity_is_specific_quantity_times_mass
    laws.quantities.quantity_is_volumetric_density_times_volume