( This ( ( is ( ( ( spring ( potential energy ) ) or ) ( elastic ( potential energy ) ) ) ) . ) )
(ROOT (S (NP (DT This)) (VP (VBZ is) (NP (NP (NN spring) (JJ potential) (NN energy)) (CC or) (NP (JJ elastic) (JJ potential) (NN energy)))) (. .)))
This is spring potential energy or elastic potential energy.
(ROOT (S (NP (DT The) (ADJP (NN term) (JJ elastic)) (JJ potential) (NN energy)) (VP (VBZ is) (VP (VBN used) (S (VP (TO to) (VP (VB describe) (S (NP (JJ potential) (NN energy)) (ADJP (JJ due) (PP (TO to) (NP (NP (DT an) (NN object) (POS 's)) (NN shape)))))))))) (. .)))