( ( Mechanical waves ) ( , ( ( unlike ( electromagnetic waves ) ) ( , ( ( ( require ( ( the presence ) ( of ( a ( material medium ) ) ) ) ) ( ( in order ) ( to ( ( transport ( their energy ) ) ( from ( ( one location ) ( to another ) ) ) ) ) ) ) . ) ) ) ) )
(ROOT (S (NP (JJ Mechanical) (NNS waves)) (, ,) (PP (IN unlike) (NP (JJ electromagnetic) (NNS waves))) (, ,) (VP (VBP require) (NP (NP (DT the) (NN presence)) (PP (IN of) (NP (DT a) (NN material) (NN medium)))) (SBAR (IN in) (NN order) (S (VP (TO to) (VP (VB transport) (NP (PRP$ their) (NN energy)) (PP (IN from) (NP (NP (CD one) (NN location)) (PP (TO to) (NP (DT another)))))))))) (. .)))
Mechanical waves, unlike electromagnetic waves, require the presence of a material medium in order to transport their energy from one location to another.
(ROOT (S (NP (JJ Mechanical) (NNS waves)) (VP (VBP require) (NP (NP (DT a) (NN material) (NN medium)) (PP (JJ such) (IN as) (NP (NP (NN water)) (, ,) (NP (NN air)) (, ,) (CC or) (NP (NN rope)))))) (. .)))