( ( Waves ( like this ) ) ( ( are ( called ( mechanical ( because ( ( the energy ) ( is ( ( ( transmitted ( through ( a ( material medium ) ) ) ) , ) ( without ( ( a ( mass movement ) ) ( of ( ( the medium ) itself ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNS Waves)) (PP (IN like) (NP (DT this)))) (VP (VBP are) (VP (VBN called) (S (VP (VBG mechanical) (SBAR (IN because) (S (NP (DT the) (NN energy)) (VP (VBZ is) (VP (VBN transmitted) (PP (IN through) (NP (DT a) (NN material) (NN medium))) (, ,) (PP (IN without) (NP (NP (DT a) (JJ mass) (NN movement)) (PP (IN of) (NP (NP (DT the) (NN medium)) (ADVP (PRP itself)))))))))))))) (. .)))
Waves like this are called mechanical because the energy is transmitted through a material medium, without a mass movement of the medium itself .
(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)))))) (. .)))