def scale(v,sc):
    """Scale a vector.

    Parameters
    ----------
    v : list
        A 3D vector.
    sc : int or float
        A scaling factor.

    Returns
    -------
    tuple
        Returns `v` scaled by `sc`.

    Examples
    --------
    >>> from .pycgmKinetics import scale
    >>> v = [1,2,3]
    >>> sc = 2
    >>> scale(v, sc)
    (2, 4, 6)
    """
    x,y,z = v
    return (x * sc, y * sc, z * sc)