It’s long been said that a penny thrown from a skyscraper could kill someone if it hit them on the head, but city workers can relax, because this is just an urban myth, according to a recent study.
Physicist Louis Bloomfield from the University of Virginia used a wind tunnel to replicate a penny falling from a great height – and they actually fall more like a leaf than a torpedo.
The results show that air resistance combined with the penny’s shape stops it becoming a lethal weapon.
Its flatness increases air resistance to the extent that it would only reach a terminal velocity of 25mph on its way down – after 50 feet – with anyone in the firing line unlikely to feel any pain at all if they were struck by one.
If there was no air at all, a penny would hit 208mph and at that speed would be capable of inflicting serious injury, but even then it wouldn’t be able to penetrate the skull.
Bloomfield placed himself in the firing line during his experiments, and reported a pain-free experience. He told Scientific American: ‘I think one bounced off my face once.’
He added: ‘A penny is pretty much a little nothing. It’s not a very compact object. It doesn’t drill into you very well.’
A ballpoint pen, however, does.
