ELI5, why if you jump inside a moving train you will land on the same spot, but if you jump on the roof of a moving train, you land on a different spot?

Question

seen it on twitter and I can’t get my head around it
EDIT: thanks guys I get it now 😅

In: Physics

Answer 1

Air resistance.

In both cases, before you jump you are travelling at the same speed as the train.

If you jump inside the train then all the air on the train is also travelling at the same speed as the train so it doesn’t slow you down.

If you jump on the roof of the train, the air is not moving at the same speed as the train so it effectively pushes you in the direction opposite to the train’s travel.