Train car A is at rest when it is hit by train car B. The two cars, which have the same mass, are stuck together and move off after the collision. How does the final velocity of train cars A and B after the collision compare to the initial velocity of train car B before the collision?

Place several e-field sensors at a few points on different equipotential lines, and look at the relationship between the electric field and the equipotential lines. which statement is true? 1-at any point, the electric field is perpendicular to the equipotential line at that point, and it is directed toward lines of higher voltages. 2-at any point, the electric field is perpendicular to the equipotential line at that point, and it is directed toward lines of lower voltages. 3-at any point, the electric field is parallel to the equipotential line at that point.