( ( The velocity ) object )
(ROOT (S (NP (DT The) (NN velocity)) (VP (VBP object))))
The velocity object
(ROOT (S (NP (JJ Instantaneous) (NN velocity)) (VP (VBZ is) (VP (VBN defined) (PP (IN as) (NP (NP (DT the) (NN velocity)) (PP (IN of) (NP (DT the) (NN object))))) (PP (IN at) (NP (DT a) (VBN given) (NN moment))))) (. .)))