( Frequency ( ( is ( ( how fast ) ( ( an object ) ( ( vibrates and ) ( ( sound vibrates ) ( in waves ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Frequency)) (VP (VBZ is) (SBAR (WHADVP (WRB how) (RB fast)) (S (NP (DT an) (NN object)) (VP (VP (VBZ vibrates)) (CC and) (VP (VB sound) (NP (NNS vibrates)) (PP (IN in) (NP (NNS waves)))))))) (. .)))
Frequency is how fast an object vibrates and sound vibrates in waves.
(ROOT (S (PP (IN In) (NP (NN science))) (, ,) (NP (NN sound)) (VP (VBZ is) (VP (VBN defined) (PP (IN as) (NP (NP (DT the) (NN transfer)) (PP (IN of) (NP (NN energy))))) (PP (IN from) (NP (NP (DT a) (JJ vibrating) (NN object)) (PP (IN in) (NP (NP (NNS waves)) (SBAR (WHNP (WDT that)) (S (VP (VBP travel) (PP (IN through) (NP (NN matter)))))))))))) (. .)))