Q4. Can you think of an easy & safe experiment we can do to prove this?

  Here is a Q that I can't wrap my brain around.

1. If you are on top of a train, running from back to front, does that mean that you're going faster than the train?

2. If you were to jump off the train after the initial run, will your distance be farther than if you jumped without running?

3. If you dropped a rock from the train to hit an oncoming signboard. will the impact be the same as if you were to throw that same rock at that sign board (while on that train)?

Explanation and links appreciated.