parkour
rallain | December 16, 2009Maybe this could fall under my "physics of parkour". It could also apply to the MythBusters "dumpster diving" episode. In both of these cases, the question is: how far can you jump off of something and not severely hurt yourself. They do this a lot in parkour. Here are some examples:
There are a ton of these things on youtube. Let me go ahead and say it. I would not recommend trying any of this stuff. Even reading this blog won't adequately prepare you. So, if you go ahead and try to do some cool jump, don't blame me for your injuries.
Now that the warning is out there - let me get on…
rallain | August 21, 2009Forgive me if I don't know the official parkour term for this move. This is where you have two walls that are close to each other and you vertically climb them. Here is a shot of Mark Witmer (from Ninja Warrior) doing the wall climb.
Doesn't look too hard, does it? Well, I think it depends on how far apart the two walls are. This is actually one parkour move that my kids like to do (Hey kids! Don't do that! Let me get my camera though because this will be perfect for my blog)
I am going to start with this second kind of wall climb. Simply because it is easier due to symmetry. So,…
rallain | August 5, 2009Parkour: the act of running and jumping like a crazy superhero. I can't do any of it. But I can analyze it. So, let me start with the wall-flip (or any kind of move that involves walking on vertical walls). This looks like a good example (there are a bajillion on youtube).
Pretty cool, huh? How do you run up a wall? Well, it has to do with friction. Remember, this is a fairly useful model for the magnitude of the frictional force on an object:
Where N is the force the surface exerts on the object (the normal force) and ?s is the coefficient of static friction. Note that this less…
