• Question: Okay so my question is; when travelling in a moving train/car/etc, when we drop something in front of us, why doesnt it fly back when we drop it? eg. a train is travelling north at 100kmph, i drop an empty bottle, it lands right in front of me. Why does it land infront of me instead of flying back south and then hit the floor?

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Great question! I’ll answer it better now than I could have in the live chat!

The answer to your question revolves around what’s known as “relative motion”. When the train is moving, everything inside the train is moving at 100kmph, this includes the bottle and you. When you drop the bottle, it is still moving at the 100kmph because it cant suddenly lose that speed. Because you are travelling at the same speed as the bottle it looks like it falls straight down!

Another way to look at this would be to think about what happens if you throw a ball out of a car window when it is moving. Does the ball just stop when it hits the ground or does it keep moving for a while before it stops?!

I hope that helps answer your question! Let me know if you want anything else explain. And don’t forget to vote! 🙂

Hi,