A bullet leaving the muzzle of an M-16 rifle has a momentum of 85 kg m/s, this will definitely kill you.
A penny, which weighs 2.35 grams (or 0.00235kg) would need to be travelling at 36,000 m/s to or almost 130,000 km/hour to achieve the same kind of momentum.
Assuming the terminal velocity of the penny in Earth's atmosphere to be around 100 m/s, the maximum momentum of the penny is 0.235 kg m/s.
A baseball travelling at 1.6 m/s (about 5.7 km/h or 3.6 mph) has the same momentum as the penny. It's unlikely that a baseball travelling at this speed will kill you.
I guess a penny might hit someone edge on (rather than flat), then the force would be more concentrated than in the baseball example, but it would seem that you would have to be pretty unlucky to suffer serious injury as a result.
so in summary, a coin can only reach a maximum velocity when dropped from a height because of a constant gravitational force and the mass of the coin itself. so it will not do you too much damage if dropped from any height. yes it will hurt but not to the point you would collapse in a heap of agony. i saw a show called mythbusters where they recreated the maximum force and proved it and there was only red marks being made. which inspired me to do my own experiment which led to an aching head but not real damage. a variety of distances and coins were used
fun with science!
so theres a bit of education for you all
thanks for your time
