( Weight ( ( is ( ( the force ) ( of ( gravity ( on ( an object ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Weight)) (VP (VBZ is) (NP (NP (DT the) (NN force)) (PP (IN of) (NP (NP (NN gravity)) (PP (IN on) (NP (DT an) (NN object))))))) (. .)))
Weight is the force of gravity on an object.
(ROOT (S (NP (NNP Weight)) (VP (VBZ is) (NP (NP (DT the) (NN force)) (PP (IN of) (NP (NN gravity))))) (. .)))