( ( ( centripetal , ) ( magnetic ( or ( electrostatic forces ) ) ) ) ; )
(ROOT (NP (NP (NN centripetal)) (, ,) (NP (JJ magnetic) (CC or) (JJ electrostatic) (NNS forces)) (: ;)))
centripetal, magnetic or electrostatic forces;
(ROOT (S (NP (JJ Centripetal) (NN force)) (VP (VBZ is) (NP (NP (DT the) (NN force)) (SBAR (WHNP (WDT that)) (S (VP (VBZ causes) (NP (JJ centripetal) (NN acceleration))))))) (. .)))