( Basically ( , ( ( objects ( that ( are ( in motion ) ) ) ) ( ( change ( their position ) ) . ) ) ) )
(ROOT (S (ADVP (RB Basically)) (, ,) (NP (NP (NNS objects)) (SBAR (WHNP (WDT that)) (S (VP (VBP are) (PP (IN in) (NP (NN motion))))))) (VP (VBP change) (NP (PRP$ their) (NN position))) (. .)))
Basically, objects that are in motion change their position.
(ROOT (S (PP (IN In) (NP (NN science))) (, ,) (NP (NN motion)) (VP (VBZ is) (VP (VBN defined) (PP (IN as) (NP (NP (DT a) (NN change)) (PP (IN in) (NP (NN position))))))) (. .)))