6. Two train cars approach each other, one of mass 113,000 kg traveling at 1.20 m/s, the other of mass 75,000 kg traveling at 2.30 m/s. After the collision, the two cars lock together. What
is the velocity of the cars after the collision? (round your answer to 1 decimal point)

When can a theory be modified if a new type of technology allows for new observations that raise new questions? a-immediately, while the questions about the theory are being asked b-after new hypotheses related to the theory are tested in experiments c-only after the new observations disprove all parts of the theory d-while scientists begin to think about how the theory could improve