I have following setup: superclass Vehicle with atribute capacity and two subclasses Bus and Tram. All trams have the same capacity as well as all busus (it should be static atribute), but capacity of a tram may be different from capacity of a bus. How to implemnt such approach in Java?

I have partially solved the problem just ignoring the fact that capacity should be static attribute for all subclasses (no static atributes).