Throwing things in cars

[Goody]

If I travel at 70 mph in a car and throw a coin up, why doesn't it smash through the rear window?

[Stewart]

Because it is also travelling at 70mph, and so is the air in the car. If you want to prove this, try it with a piece of paper in an open topped car!!! Not very scientific but dramatic enough to be conclusive.

[Stewart]

If you drop the coin from a bridge into the car through the sunroof, then it probably would go through the back window.

[haller]

momentum. THE END.

[WaldoMcFroog]

Actually, an even better question - which illuminates why your question doesn't matter - would be: How come if we jump straight up, we land in the same place, seeing as the Earth is moving at 1670 kph (at the equator)? As the others have explained, it's becuase everything experiences the Earth's rotation.

[AndyAvery]

If you drop the coin and then accelerate extremely hard it will move backwards a bit, just like you get pressed into your seat when you accelerate hard, suspect most cars would be incapable of accelerating fast enough to send it through the window :-)

[Pinotage]

I thought this question was answered by Einstein in his Theory of Relativity