( Centripetal Force )
(ROOT (NP (NNP Centripetal) (NNP Force)))
Centripetal Force
(ROOT (S (NP (JJ Centripetal) (NNS forces)) (VP (VBP cause) (S (NP (NNS objects)) (VP (TO to) (VP (VB turn) (PRT (RP around)) (ADVP (RB continuously)) (PP (IN in) (NP (DT a) (NN circle))))))) (. .)))