“What happens if you drop a penny on some one from the CN Tower?
“It’d split you in two!”
– Many more people
Let’s go ahead and figure this out.
There will be enough force from the penny to do serious damage, such as a concussion, or a skull fracture.
The CN Tower is located in Toronto, ON. We need a place outdoors with no barriers. The drop will occur from the CN Tower’s Edge walk, 356 meters above the ground. 1.8 meters is then subtracted, because the head of the test subject is that high off the ground.
H = 354.2 m
Pennies were manufactured in Winnipeg by the Royal Mint. Their website will have the information we need. We will use a penny made in 2012, which weighs 2.35 grams.
W = 2.35 g
After a quick unit conversion and a bit of math, we determine that the velocity of the penny is 83.32 m/s.
After even more math, it has been determined that the KE of the penny is 8.157 Joules. One joule is equal to one newton, so now we need to covert that to pounds.
The impact force of the penny being dropped off the tower is…
That is barely anything. It weighs so little as well, that the chance of it hitting you are slim because of the wind. If it hit you one edge, it might leave a little mark. That’s disappointing.
But wait, there’s more!
Pennies come from the bank in rolls of 50. Let’s drop the other 49 off just to be “safe”.
49 pennies at 2.35 grams will weigh in at 115.15 grams. That’s our new weight, height stays the same.
(Math and physics magically occur!)
The new impact is 89.856 pounds!
Round 2.The test subject is standing at the base of the CN Tower, looking up and trying to figure out why a penny just landed on his head. All of a sudden, a brown object comes hurliing towards him at ~80 m/s, and collides with his nose.
The test subjects nose is broken is several places, with parts of it being pushed back into the skull. He is instantly knocked out and will have Grade III concussion (The worst kind). There will be heavy bruising.
We’re not done yet.
Pennies come from the bank in boxes of fifty rolls. We’ve only used one, so we’ll chuck the remaining 49 off the edge for good measure. The new weight is 5.7575 Kg. This is going to hurt, so we’ll skip to the outcome.
The test subject is trying to explain to the police officer what happened. The officer seems unsure about the whole thing, and goes back to his car to call for backup. Shortly after, the box hits the test subject directly on top of the head. It first causes a linear fracture, and breaks skull over the top from ear to ear, fragmenting it and causing a shotgun like effect and injecting the skull into the brain. The force carries through, and dislocates both his shoulders, pushing them up while the rest of his body moves towards the earth. Next come the ribs, which all snap like toothpicks and cause your internal organs become a pudding. Legs buckle and break as he collapses on the ground. The box of pennies hits the earth soon after, and explode with the force of an M67 Hand Grenade sending 2,450 pennies into the surrounding area. The policeman returns to find the test subject buried in a field of pennies.
Final impact force: 4.492 Tonnes
The force needed to break your skull in two (Linear Fracture) while standing is so significant, that it would kill you before the rest happens. You would not split in two, but instead turn you into a “human accordion”.
If I ask to visit a bank before doing the CN Tower edge walk, call the police and show them this article.
Thanks for reading!
This was originally a presentation I made for a Grade 12 English coffee house in Nov. 2013 on the subject of my choosing (I got a 97%).
It was inspired by the XKCD What if? articles.