Awesome.
Just.
Awesome.
{kicking myself for not joining the Straight Dope Message Board until this past week}
Just one, provided… you drop it on someone just as they look up, their mouth open in complete shock of having a pie being dropped on them from 50 stories, and they then choke on the bit that just got stuffed down their windpipe.
Whatever happened to people going beyond the obvious equations? Has no one considered Ft=m(vo-vf)? Time of collision is what you people keep calling “squishiness.” For instance, if you drop an egg on a pillow versus concrete. The pillow is squishy, therefore allowing the collision to take place over more time. Concrete’s time of impact is smaller, therefore causing the force to be larger. One could find the applied force if the collision time was known, though the answer likely would not mean much to the average Joe anyway.
And I thought I didn’t have a life!
this is the SDope, we have had 44 posts, and nobody has yet asked:
what happens if you put the pumpkin on a treadmill?
(I’m sorry…
…yeah, really really sorry…
…but somebody had to say it…)
Treadmills are usually really heavy. It will kill whoever it falls on whether or not there’s a pumpkin involved.
But if you’re going to get into deformations, you have to use techniques like finite-element analysis to do things like calculating the wavefront of the impact as it travels through the pie material, figuring out how and when the pie material will disrupt, and so on. For that you need a pretty powerful computer, the kind usually used for calculating nuclear explosions and planetary impacts. Are you sure you want to go to that level of detail? Because if you do, you’ll have to tell me how to do it.
But isn’t that the point? If you really want to figure this kind of thing out while considering the pumpkin’s squishiness like everyone keeps bringing up, it’s going to have to take more math and less speculation. That, or experimentation. Frankly, if assumptions mattered, I would venture to say that the pumpkin is hard enough to give you a concussion, if not kill you. Although, it depends on how thick skulled you are…
I strongly disagree with this. There’s no need to do a FEA if we know the material properties, specifically it’s Young’s modulus and shear modulus. I’m taking an impact analysis class this semester, and we haven’t even mentioned finite at all.
Nope, nobody ever thought of that.
;)
I figured out why I disagreed so strongly with your statement. The level of complexity of this system is very basic for a consumer level FEA software (COSMOS and ANSIS, for example), and can be done on a very basic PC. Heck, five years ago some guys from ANSIS came to our class and showed us a model of a turkey flying into a jet engine. The simulation was run on one of the computers in the lab, which were maybe 1 GHz machines. Hydrodynamic simulations (i.e. nuclear explosions) are generally modeled on large machines like the RoadRunner, but a simple object colliding with another simple object (skull) is child’s play.
While I was in China, I visited the home of a Chinese citizen. In his garden, he had trained pumpkin vines onto several branches of a tree. So I’ve actually seen what might be called a pumpkin tree. Of course, it could equally well be called something else.
Cool! Can you give or point us to a demonstration? I’m really curious now.
:dubious:
We are talking about another pumpkin, I promise.
Should they throw frozen pumpkins through the jet engines to test them in addition to the frozen turkey? Also do frozen cranberries make a good substitute for hail in wind tunnel tests?
I don’t currently have a license for any FEA programs, but here’s a couple of examples:
Here’s a page with a tutorial of how to model a simple cantilever beam subjected to an impulse force. For some reason, I used to get a lot of Canadian university websites when I was looking for help with ANSYS in college, too.
Here’s a youtube video of a cylindrical container being exposed to an external pressure (a soda can would be one example).
Here’s a buggy frame being subjected to a crash (i.e. dynamic) test.
There are much cooler models out there, but I’m having trouble finding ones that you don’t have to sign up to ANSYS or COSMOS for. The last one is quite a bit more complex than the falling pumpkin situation, and is not even touching the computing power of a modern desktop.
Keep in mind that (as I think somebody said) comparing the computer model to a physical test is imperative to ensure integrity of both the test results and the computer program as a whole. Fortunately, now you can do that right in the software.
I don’t see why not. And if you shot them through the jet engine, you could make cranberry sauce without having to mash or cook them!
WOW! I signed up at the ANSYS website to see if they had any downloadable demos I could post. I just got a call from one of their representatives asking if I needed help finding anything or needed to be directed to their local reseller. I can only hope that their customer service is that prompt when the software has already been purchased.
No, whenever somebody has to risk death on Mythbusters, they always send in Tory. Without fail. I approve - he’s the most expendable. Plus, it’s fun to watch him get hurt.
It’s also fun to watch Adam get hurt, but if Adam ever got killed, Jamie would become incredibly boring. So it’s got to be Tory.
Don’t they usually reserve those jobs for Buster?