Draw diagrams showing a situation where a bigger, moving train, vi, collides with a smaller train that is not moving. Assumer that after the collision the trains stick together. Show separate diagrams for the situation just before the collision and just after the collision. Assume the trains have different masses (m-big, and m-small). Make sure you identify your isolated system. Write down the momentum conservation equation for the scenario in question. Solve for the final velocity of the two trains Vf in terms of Vi, m-big, and m-small.