Pinga Lick'in GoodPosted by: Maybelline@ Holy smokes, what a crazy and exciting week it has been! The Firebird Festival has come to end, but please don’t be sad. Our awesome feathered friends will be back again next year to celebrate with us once more. This week we will pay a visit to my friend and see what he has going on at the @Finneous+Boutique con Carne. Do you think you have what it takes to get through this Enigma with a glorious reward or will you fall into my trap? Good luck, everyone!I am astonished by how many people I stumped with this one! I guess this was a lot harder than I intended. I am sorry! As with the last Enigma, there were a couple of ways to solve it but for those that I did manage to confuse, here’s how to easiest way to solve this puzzle. First off, think of the sparkler as a flat 2D object rather than a 3D one. Cutting and unrolling the cardboard tube from a roll of paper towels will give a 2D representation of what this would look like. Convert the inches to centimeters for the total length of the sparkler. 15.748 inches = 40 centimeters 6/8 of length of the total length of the sparkler is 30 centimeters. This is the portion of the wooden base that is covered by the explosive cord. The space between each coil can be figured out by 30 cm total space / 10 coils within the space; 3 cm.Using the Pythagorean Theorem; we will be able to solve for how long 1 coil is or C in the above diagram. From above we know: A = 4 cm [diameter of the sparkler] and B = 3 cm10 coils per sparkler = 50 cm of explosive coil needed per sparkler1250 centimeters of explosive cord is needed to make the entire box of Seregan Sparklers.15 people participated and 0 got it correctI have an honorable mention to @Charles as their guess of 3141.593; was the closest.
- Brian@
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5/19/2017 @ 5:11 pm
To be fair to
@Maybelline@, I really don't think she meant that sarcastically, and I don't think she was trying to make anyone feel stupid. i can understand how it could come off wrong though. I think she was just trying to explain where you would learn how to do that, not say like "oh an 8th grader would know this." - Maybelline@
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- weee5067
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5/19/2017 @ 7:30 pm
I'm actually pretty sure the official answer is wrong. 'a' shouldn't be the diameter of the rod, it should be the circumference (you aren't dropping a weight on a cylinder and smashing it flat, you're unrolling it). If you don't believe me, try actually wrapping a piece of floss around a paper towel roll 10 times and then measuring it. Your calculation should be off by roughly a factor of 3 (actually pi).
(I can only complain so much, since I forgot to multiply my answer by 25 and therefore didn't get it right anyway. @Charles was, in fact, extremely close, though.)- Kitty
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5/19/2017 @ 11:46 pm
I agree that you can't use the diameter of the rod to calculate coil length as shown above unless you account for circumference another way, e.g. by making the problem 3d. Like
@weee5067, I still got the problem wrong since I didn't account for the slant of the coils, but I'm not sure this is correct either.- ss
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5/20/2017 @ 12:21 am
Thank you weee for bringing it up, that's what I meant about the formulas I found being more complicated. Some would ask for the space between the coils, and all of them included pi. I personally was wary of the question because I've never been taught how to work with a 3D shape like that, but I thought there must be ways to do it with the information supplied.
Ironically, my dad used to do engineering blueprints and could have probably told me very quickly what goes where and if something was missing from the question. I'll try to remember to ask him after I've slept. - weee5067
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5/20/2017 @ 4:46 am
Oh, that's not all! By giving the cord thickness, you've turned the problem into a question of semantics as well.
If you take a 3-inch-thick metal rod and bend it into a circle, you'll need to cut the ends of the rod at an angle to perfectly join them ("The cord wraps around the wood precisely and evenly 10 times." seems to imply that the ends of the cord would line up perfectly). So, what's the length of the final, circular rod? Is it the circumference of the inner circle? Is it the circumference of the outer circle, calculated using a diameter 6 inches greater? Is it the length measured through the center of the rod? Is it the length of the cylinder you'd get if you reshaped the slanted rod into a right cylinder with a 3-inch diameter and equal volume? I have no idea, and I think you can make a pretty good argument for any of those choices. |

Now I don't feel so stupid for never finding an answer that seemed right.

Edit: damn, wrong link. I can't find the other sites it was forum posts and so on with a lot of ASCII diagrams, haha.