Q. It is advised not to stand near a running train. Why?
Ans. When fast moving train passes on a rail, than the velocity of air streams in between the rail and the person standing near rail will be very large as compared to the velocity of air streams on the other side of person away from the rail. According to Bernoulli’s theorem, the pressure of air will become low in between person and rail and is high on the other side of person. As a result of the pressure difference, a thrust acts on the person which may push the person towards rail side and the person may meet with an accident