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I cheated and looked at the answer but on the Internet no one knows what you cheat so my answer is still legit right? X3
math teaser - Page 2
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nayumi
Australia6499 Posts
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endy
Switzerland8970 Posts
On August 18 2010 15:45 AlienAlias wrote: Yeah, it's definitely one of my favorite teasers. Realistically, you'd think that adding a little bit of length to a rope that goes around the world would do nothing, considering how massive the world is, but when you think about it analytically the circumference and radius relate directly at a certain ratio (c = (pi)2r) so it doesn't matter what the previous radius was. Exactly, you could do this with the sun or the whole solar system, and adding 3 feet of length to the rope would still lead to a 6 inches gap ! | ||
]343[
United States10328 Posts
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Luddite
United States2315 Posts
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rockon1215
United States612 Posts
Circumference = 3 Solve for r r ~.477 cm Could of done this in 6th grade. Let's see something harder  | ||
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Vinnesta
Singapore285 Posts
On August 18 2010 17:55 rockon1215 wrote: Circumference = 2*pi*r Circumference = 3 Solve for r r ~.477 cm Could of done this in 6th grade. Let's see something harder The circumference is in feet, and so should r. In fact, I think this is the wrong way of solving the problem; the circumference is not equal to 3 feet. You might also have learnt in 6th grade that "could of" is not a correct substitute of "could have"... OT: The answer to this puzzle is really hard to imagine! A few feet added to something as large as the circumference of the Earth produces such a massive gap?! | ||
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Count9
China10928 Posts
On August 18 2010 21:21 Vinnesta wrote: The circumference is in feet, and so should r. In fact, I think this is the wrong way of solving the problem; the circumference is not equal to 3 feet. You might also have learnt in 6th grade that "could of" is not a correct substitute of "could have"... OT: The answer to this puzzle is really hard to imagine! A few feet added to something as large as the circumference of the Earth produces such a massive gap?! what exactly is the "right" way to solve the problem? | ||
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Nytefish
United Kingdom4282 Posts
On August 18 2010 12:33 saltywet wrote: try to guess it before looking at answer or doing any calculationse Should have stuck that at the top, people don't like to read carefully  I don't usually hear questions like this posed as a 'math teaser' because that often gives it away. The idea is that typical human intuition is bad when dealing with very large (or small) things. If you stick math in the title it will ward off all the people who would've been mindblown by it ;( On August 18 2010 21:21 Vinnesta wrote: The circumference is in feet, and so should r. In fact, I think this is the wrong way of solving the problem; the circumference is not equal to 3 feet. You might also have learnt in 6th grade that "could of" is not a correct substitute of "could have"... OT: The answer to this puzzle is really hard to imagine! A few feet added to something as large as the circumference of the Earth produces such a massive gap?! I don't think he means circumference of either of the rings, just the change in circumference. Which you can use to find the change in radius. | ||
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zer0das
United States8519 Posts
On August 18 2010 15:26 endy wrote: It's not floating 3 feet off... I admit the "nothing" in the premise was confusing, but I found the problem intersting as the final results is a lot different that what I expected. Whoops... 5 inches. Point still stands. | ||
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saltywet
Hong Kong1316 Posts
the floating part is part of the premise and ti doesnt matter, u can say whatever u want the earths magnetic field somehow repels it away from the surface of the planet the point of the math teaser is that most people dont expect that the change in circumference can actually create that large a difference in radius on something as large as the earth and yeah, i guess i should have put "try to guess without looking at answer or doing calculations" at the top in big bold letters | ||
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