The penny from the Empire State Building:
In theory, it should travel faster than a bullet. Emptying your pockets should make you a serial killer on top of the building. I won't bore you with the equation. Even if a penny was fired with a gun from the top of the building, it cannot kill anyone. WHY?
All objects have a terminal velocity. The terminal velocity of a penny is about 65 mile/hour. Try this: tape a penny from an over-pass bridge and drive 65MPH, stick your head out, WHAM,...That's all.
*With the internet, you can just google it, or watch it on Myth Buster(Season 3 episode 4).