( ( The momentum ) ( ( is ( equal ( to ( ( the mass ) ( of ( ( the gun ) ( multiplied ( by ( its velocity ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN momentum)) (VP (VBZ is) (ADJP (JJ equal) (PP (TO to) (NP (NP (DT the) (NN mass)) (PP (IN of) (NP (NP (DT the) (NN gun)) (VP (VBN multiplied) (PP (IN by) (NP (PRP$ its) (NN velocity)))))))))) (. .)))
The momentum is equal to the mass of the gun multiplied by its velocity.
(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-)))))))))))))) (. .)))