momentum and its position remains mostly undeterminable 
(ROOT (S (NP (NP (NN momentum)) (CC and) (NP (PRP$ its) (NN position))) (VP (VBZ remains) (ADJP (RB mostly) (JJ undeterminable)))))
(ROOT (S (NP (NP (NN )) (CC ) (NP (PRP$ ) (NN ))) (VP (VBZ ) (ADJP (RB ) (JJ )))))