cross-posted from: lemm.ee/post/29980757
Let π = 5
I smell a quantum mechanics professor there.
Let π = 5
Submitted 8 months ago by ElCanut@jlai.lu to science_memes@mander.xyz
https://files.catbox.moe/hjclod.jpg
Comments
Sagar@sopuli.xyz 8 months ago
tormeh@discuss.tchncs.de 8 months ago
Astronomers would round pi to 1.
Tlaloc_Temporal@lemmy.ca 8 months ago
Or 10, whatever. The precise value is only relevant when measuring the curve of space, and they’ll still disagree with mathematicians on most of the digits.
chuckleslord@lemmy.world 8 months ago
fckreddit@lemmy.ml 8 months ago
Ancient Greek Mathematicians would be so disappointed. Even they knew that pi is between 3.1 and 3.2.
Omega_Haxors@lemmy.ml 8 months ago
POV your state just mandated you round pi to the nearest integer (this has happened a few times, but it never sticks)
ElCanut@jlai.lu 8 months ago
It has happened??
Omega_Haxors@lemmy.ml 8 months ago
All the time, though usually never goes as far as actually passing. It’s rare that it does make it to law, but it does happen.
jordanlund@lemmy.world 8 months ago
Well, with those numbers, it’s easy math. :)
V=510^210
5,000. 5,000 what though?
Even with a proper π value, it still doesn’t make sense… 3,141.59265359
EddoWagt@feddit.nl 8 months ago
What? Its just the volume, without units. What part of it doesn’t make sense?
jordanlund@lemmy.world 8 months ago
Well, a r=10 and h=10 doesn’t mean much without units. 10 what? Feet? Meters? Inches? CM?
Let’s take the OG numbers and assume feet, so 5,000 cubic feet. That’s not a useful volume measurement.
1 cubic foot of water = 7.48052 gallons
So 5,000 cubic feet of water = 37,402.6 gallons. That’s a viable volume measurement.
1 cubic meter = 1,000 liters.
5,000 cubic meters = 5,000,000 liters.
Evilsandwichman@hexbear.net 8 months ago
They’re rounding down
tulliandar@lemmy.world 8 months ago
gimpchrist@lemmy.world 8 months ago
As a dyscalculic, I can’t solve this but I don’t see a problem here… I see all you people freaking out that the little symbol thing equals five but it’s a little symbol thing haha it doesn’t have to be pie haha it could be a little symbol thing.
leavemealone@sh.itjust.works 8 months ago
You should write"come see me after class* as your answer.
Thunderwolf@lemmy.world 8 months ago
There are people that think this post is wrong because the equation is wrong or due to a lack of units
The equation for cylindrical volume is correct (circular area multipled by height).
And the units are unimportant (can be described as cubed units)
The issue is that Pi is a constant. Constants and variables are different things.
Other examples of constants: 1, 24, 7, -1 … Etc.
Saying Pi = 5 is like saying 1 = 5 … Both Pi and numbers like 1,2,3, etc. have a constant (non-varying) value.
You can’t reassign a value on a constant. It’s like me sticking up 3 fingers and claiming there are 5 fingers there.
CameronDev@programming.dev 8 months ago
For the purpose of teaching young school kids how to substitute real values for constants/variables, does it matter? π is a constant, but the value you use for it in exams and real life will not be the same, or the actual correct value. Getting students used to the idea that even constants can have varying values in exams or software is useful.
In my exams π had values ranging from 3, 3.1 to whatever the calculator had.
galso ranged from 9.8 to 10, although in fairnessgis not a constant.At least setting it to 5 can spark debate around what a more reasonable approximation should be.
new_guy@lemmy.world 8 months ago
OP’s problem isn’t even wrong.
It’s just assuming that π is 5 in this specific scenario, just like it’s reasonable to assume the existence of a spherical cow in a frictionless environment. Yeah, if you use the results of this problem to develop a real cylinder you’re going to have a bad time but nobody is doing that all what’s the problem?
Nobody is saying that from this point in time and going forward π = 5 and now math is broken forever. People need to chill
bobs_monkey@lemm.ee 8 months ago
If it’s teaching grade school kids, I would argue it is problematic, only as to not draw confusion on reassigning π away from it’s widely accepted consistent value of ~3.14 for most applications. Once you start getting into theoretical physics and the like, that’s a different story. Math is already a tough subject for many kids and this would just throw another wrench into the learning curve. I’d argue to only start debating the fundamentals and theory after a firm grasp of the fundamentals has been established and practiced repeatedly, preferably in upper level courses.
vox@sopuli.xyz 8 months ago
i had to solve a couple of problems with stuff like “assuming pi = 3”,… usually to make solving stuff without calculator easier
MinekPo1@lemmy.ml 8 months ago
minor nitpick but the value of π is technically a parameter of the space you are operating in . which means it can have any arbitrary value as long as you are willing to operate in non euclidean spaces (and the space we live in is not euclidean though not to a measurable extent unless you are near a black hole)
but yeah in this context saying π is a constant is as correct as saying you cant take a square root out of a negative number .
Orbituary@lemmy.world 8 months ago
Ok, Picard. There clearly are 3.