( ( According ( to ( ( Archimedes ' ) law ) ) ) ( , ( ( ( ( an object ) ( ( ( with ( an ( average density ) ) ) less ) ( than ( that ( of ( the liquid ) ) ) ) ) ) ( ( in which ) ( it ( 's submerged ) ) ) ) ( ( will ( float upward ) ) . ) ) ) )
(ROOT (S (PP (VBG According) (PP (TO to) (NP (NP (NNP Archimedes) (POS ')) (NN law)))) (, ,) (NP (NP (DT an) (NN object)) (PP (PP (IN with) (NP (DT an) (JJ average) (NN density))) (CC less) (PP (IN than) (NP (NP (DT that)) (PP (IN of) (NP (DT the) (NN liquid)))))) (SBAR (WHPP (IN in) (WHNP (WDT which))) (S (NP (PRP it)) (VP (VBZ 's) (VP (VBN submerged)))))) (VP (MD will) (VP (VB float) (ADVP (RB upward)))) (. .)))
According to Archimedes' law, an object with an average density less than that of the liquid in which it's submerged will float upward.
(ROOT (S (NP (NP (NNP Archimedes) (POS ')) (NN law)) (VP (VBZ explains) (NP (SBAR (WHADVP (WRB why)) (S (NP (DT some) (NNS objects)) (VP (VBP float)))) (CC and) (NP (DT some) (NN sink))))))