( Archimedes ( ( ( worked out ) ( why ( ships float ) ) ) . ) )
(ROOT (S (NP (NNP Archimedes)) (VP (VBD worked) (PRT (RP out)) (SBAR (WHADVP (WRB why)) (S (NP (NNS ships)) (VP (VBP float))))) (. .)))
Archimedes worked out why ships float.
(ROOT (S (NP (NP (NNP Archimedes) (POS ')) (NN law)) (VP (VBZ explains) (SBAR (WHADVP (WRB why)) (S (NP (NP (DT a) (NN ship)) (VP (VBG weighing) (NP (NP (NNS thousands)) (PP (IN of) (NP (JJ metric) (NNS tons)))))) (VP (VBZ floats) (PP (IN on) (NP (NN water))))))) (. .)))