( ( The ( rolling motion ) ) ( ( is ( calculated ( based ( on ( ( ( the ( object dynamics ) ) and ) ( the ( desired ( critical ( contact force ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (JJ rolling) (NN motion)) (VP (VBZ is) (VP (VBN calculated) (PP (VBN based) (PP (IN on) (NP (NP (DT the) (NN object) (NNS dynamics)) (CC and) (NP (DT the) (VBN desired) (JJ critical) (NN contact) (NN force))))))) (. .)))
The rolling motion is calculated based on the object dynamics and the desired critical contact force.
(ROOT (S (NP (NNP Dynamics)) (VP (VBZ is) (NP (NP (DT the) (NN study)) (PP (IN of) (SBAR (WHADVP (WRB how)) (S (NP (NNS forces)) (VP (VBP affect) (NP (NP (DT the) (NN motion)) (PP (IN of) (NP (NNS objects)))))))))) (. .)))
Dynamics is the study of how forces affect the motion of objects.