Question Details DSColPhys1 8.3.023. [2153595] Train cars are coupled together by being bumped into one another. Suppose two loaded train cars are moving toward one another, the first having a mass of 150,000 kg and a velocity of 0.300 m/s, and the second having a mass of 125,000 kg and a velocity of -0.120 m/s. (The minus indicates direction of motion.) What is their final velocity? m/s 150,000 Kg 125, 000 kg m = 150,000 + 125,000 = 275,000 kq 0. 3 mls 0. 12 m/s V'= ? initial final collision - cons. of momentum m, v. + my Vz = (m, + my )v