( It ( ( is ( ( known ( that ( in physics ) ) ) ( that ( ( ( the mass ) ( of ( ( an object ) ( multiplied ( by ( ( the velocity ) ( of ( the object ) ) ) ) ) ) ) ) ( equals ( ( the ( liner momentum ) ) ( of ( the object ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP It)) (VP (VBZ is) (VP (VBN known) (NP (NP (DT that)) (PP (IN in) (NP (NN physics)))) (SBAR (IN that) (S (NP (NP (DT the) (NN mass)) (PP (IN of) (NP (NP (DT an) (NN object)) (VP (VBN multiplied) (PP (IN by) (NP (NP (DT the) (NN velocity)) (PP (IN of) (NP (DT the) (NN object))))))))) (VP (VBZ equals) (NP (NP (DT the) (NN liner) (NN momentum)) (PP (IN of) (NP (DT the) (NN object))))))))) (. .)))
It is known that in physics that the mass of an object          multiplied by the velocity of the object equals the liner momentum of          the object.
(ROOT (S (NP (NNP Momentum)) (VP (MD can) (VP (VB be) (VP (VBN calculated) (PP (IN by) (S (VP (VBG multiplying) (NP (NP (NP (DT an) (NN object) (POS 's)) (NN mass)) (PP (IN in) (NP (NP (NNS kilograms)) (PRN (-LRB- -LRB-) (NP (NN kg)) (-RRB- -RRB-))))) (PP (IN by) (NP (NP (PRP$ its) (NN velocity)) (PP (IN in) (NP (NP (NNS meters)) (PP (IN per) (NP (NP (JJ second)) (PRN (-LRB- -LRB-) (NP (NN m/s)) (-RRB- -RRB-)))))))))))))) (. .)))