Since I got back from holiday I have wondered how much force I might have generated on the Disneyland teacups.
I think I literally hurt my brain (and if I did, I could engage San Francisco Brain Injury Attorneys). Cameron R. Bass of University of Virginia says that the head can withstand 60 times the force of gravity, and the Wayne State Concussion Limit Curve seems to agree (although some monkeys they slammed into windshields withstood up to 85 time the force of gravity), but I think means pancaking the skull and dying. I do not want to know if I died (I did not), just if it was a concussion that made me want to sit down for a couple of hours, and, as a side curiousity, if age and concussion tolerance have an inverse relationship. I am pretty sure that I spun as fast in the teacups when I was a kid, but I do not remembering wondering if I had hurt my brain. Nowadays I wonder if there is such a thing as a brain bruise.
With a back-of-the-envelope calculation I figure my head was experiencing 5 or 6 times the force of gravity when I leaned back. I have seen The Right Stuff and know that I cannot stand as much as those supermen, but just how wussy is my brain? Going 5 or 6 Gs may not sound like a lot, but I was about to lose my $9 hamburger and fries, and then felt not-so-well for a while.
After I did the rough calculation, I wanted to refine it a bit. I estimate two variables---radius and angular momentum---to produce the third value, the force. I do not have Mathematica, but I remembered that Apple has a 3D graphing calculator that I have never used and this is perfect. I can put in the equation, set the domains, and have a nice picture that I can save with a screenshot. However, I cannot find the calculator, so no pretty force surfaces. Damn graphing calculator---there when I do not want you and missing when I need you. Damn dirty calculator!
This is the information age, however, and someone must of thought of this before. Indeed, at least one person rode every teacup and rated its force producing capabilities, but provided no hard measurements. His calculations are close to mine, though.