( ( Ignoring ( hydrodynamic effects ) ) ( , ( ( all ( ( ships or ) boats ) ) ( ( float ( because ( ( ( the weight ) ( of ( ( the water ) ( they displace ) ) ) ) ( is ( equal ( to ( ( the weight ) ( of ( ( the boat ) ( -LRB- ( ( ( Archimedes ' ) principle ) -RRB- ) ) ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (S (VP (VBG Ignoring) (NP (JJ hydrodynamic) (NNS effects)))) (, ,) (NP (DT all) (NNS ships) (CC or) (NNS boats)) (VP (VBP float) (SBAR (IN because) (S (NP (NP (DT the) (NN weight)) (PP (IN of) (NP (NP (DT the) (NN water)) (SBAR (S (NP (PRP they)) (VP (VB displace))))))) (VP (VBZ is) (ADJP (JJ equal) (PP (TO to) (NP (NP (DT the) (NN weight)) (PP (IN of) (NP (NP (DT the) (NN boat)) (PRN (-LRB- -LRB-) (NP (NP (NNP Archimedes) (POS ')) (NN principle)) (-RRB- -RRB-))))))))))) (. .)))
Ignoring hydrodynamic effects, all ships or boats float because the weight of the water they displace is equal to the weight of the boat (Archimedes' principle).
(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))))))) (. .)))