( Weight ( ( is ( ( a force ) ( on ( a ( ( mass ( due to ) ) gravity ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Weight)) (VP (VBZ is) (NP (NP (DT a) (NN force)) (PP (IN on) (NP (DT a) (ADJP (RB mass) (JJ due) (PP (TO to))) (NN gravity))))) (. .)))
Weight is a force on a mass due to gravity.
(ROOT (S (NP (NNP Weight)) (VP (VBZ is) (NP (NP (DT the) (NN force)) (PP (IN of) (NP (NN gravity))))) (. .)))