Firstly, the comments on that last post were priceless. thanks to everyone.
Alicia’s calculations were good, but they don’t take into consideration the distance he falls. Aaron is right, it has a lot to do with Kinetic energy. and until he started talking carbonated beverages, he was right on. Let’s take the climbers mass as 91 kg (200.2 lbs). we will use the height of 7 meters (21 feet). And Alicia’s calculation of velocity at impact of 11.7 m/s.
at impact: K.E. = 1/2 m v^2 = about 6230 Joules
But force of impact is also dependent on stopping power. The whole advantage of my stopping Joel is that I’d have about about 1.5 meters (5 feet) of slow down time. If Joel hit the floor, he would be stopped almost immediately and would suffer a lot more.
A Joule is defined as the amount of work done when an applied force of 1 newton moves through a distance of 1 meter. So, since I would be providing 1.5 meters of slow down, I can divide our 6230 by 1.5 to get the amount of force (in Newtons) needed to stop Joel.
6230/1.5 = 4153 N
Converting Newtons to Pound Force
4153/4.448 = 933.67 lb
So, I would feel about 933 pounds slamming down on me…. But this is only from 7 meters. The wall is 13 meters high. From 13 meters, I would get hit with about 7700 N, or 1731 lbs. For the average person, that would definitely result in serious injury. Thankfully, I’m a muscle monster and could certainly catch even the heaviest climber without a problem. 1731 pounds? walk in the park.
Authored by: mike d.
