( ( ( Potential ( and ( kinetic energy ) ) ) ( ( Potential energy ) ( ( is often ) called ) ) ) ( ( stored energy ) . ) )
(ROOT (S (NP (NP (JJ Potential) (CC and) (JJ kinetic) (NN energy)) (SBAR (S (NP (JJ Potential) (NN energy)) (VP (VBZ is) (ADVP (RB often)) (VP (VBN called)))))) (VP (VBD stored) (NP (NN energy))) (. .)))
Potential and kinetic energy Potential energy is often called stored energy.
(ROOT (S (NP (JJ Potential) (NN energy) (NN energy)) (VP (VBZ is) (VP (VBN stored) (PP (IN in) (NP (DT a) (NN person) (CC or) (NN object))))) (. .)))