Someone asked a question. If a person jumps up and down in a train carriage they land back in the same place. But if you do it on the roof you will not land in the same place. He wanted to know the reason? A lot of people replied including me. We pointed out that if the train is moving the air on the outside will be pushed aside by the train and anything on it.

I wrote ‘If you jumped on top of a train you would land on the same spot even if it was moving slowly. The reason why you might move is the air rushing around you exerts a force or pressure on you (the air inside the carriage is still). But unless you were travelling fast you wouldn’t move far… ‘.

I think it’s odd that people don’t know it. In the same way a dog who sticks its head out of a car gets its face and ears ruffled by the wind….