When a train starts, the head of a standing passenger seems to be pushed backward. Analyze the situation from the ground frame. Does it really go backward? Coming back to the train frame, how do you explain the backward movement of the head on the basis of Newton’s laws?

Question

Philoid · Accepted Answer

When the train starts, with respect to ground frame: it remains at rest. Just our feet go in front. With respect to train frame: The feet of our body come into motion along with train but the upper part of our body due to the inertia of rest tends to be at rest thus it falls backward.