How the forced capture rule works with crowned pieces( in international checkers or...)
It depends on the checkers/draughts variant that you are playing:


For American checkers / Britisch draughts (which are two names for the same game) and Italian checkers, kings are short-ranged and cannot jump over empty squares.
For all other variants (International/Russian/Spanish/Czech/Frisian/Thai draughts and Pool checkers), kings are long-ranged and can jump over empty squares as you indicated. 


NOTE: in fact, for all but one (Thai draughts) of the long-ranged king variants, kings can also land on a sequence of adjacent empty squares behind a captured piece. In your notation, this would be patterns of the form B- - -w- - -, where the black king can land on any of the three - squares behind the white man.