Question

When two trains, going in opposite directions, are passing on tracks that are laid out close together, the train cars can often be seen to be leaning in toward one another where they are in proximity. How might the air passing through the narrow gap separating the two trains contribute to the observed attraction between their cars?

Answer 1

Answer:

"Therefore, the speed of the air decreases, the pressure acting on the two trains increases (by Bernoulli's principle), and the two trains lean in toward one another."

Answer 2

When there is air in between two objects, it pulls them together because of the pressure of the air