r/theydidthemath • • 10h ago

[request] sailing

0 Upvotes

if I was sailing my boat from East to West in the ocean and during the sunset, at which speed I should sail to maintain a perpetual sunset in front of me ?


r/theydidthemath • • 13h ago

[Request] If someone were to begin counting and didn’t stop counting until they died how high could they count?

0 Upvotes

Assume they must sleep and eat and that they can begin counting at age 2.


r/theydidthemath • • 17h ago

[Request]: seems rather challenging

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1 Upvotes

Any guesses? This “era” being the last 25 years?


r/theydidthemath • • 14h ago

[Request] How does one simply calculate the speed needed to successfully (at least in theory) to do a loop-the-loop on foot?

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0 Upvotes

r/theydidthemath • • 14h ago

[Request] How many cans do I need to collect to offset cost of gas and actually make a profit?

0 Upvotes

Please help! It's too much simple math for me and we are extremely broke. I can't afford to go on a wild goose chase.

About ten miles away there is a back road that is downright littered with empty pint beer cans like bud lite and Miller lite. (I drive this way every day as a school bus driver.) I drive a 2009 Ford Explorer, and the reading is that I get about 18 miles per gallon. Gas at its lowest in the last month is about $3.44 per gallon, but high end a week ago was $3.81 a gallon. I was thinking of parking and collecting cans every quarter mile, then driving farther. The road itself is about two miles long, and there are literally thousands of cans in various states of decay, and I'm not sure if aluminum loses weight in the Texas heat over time. Let's say they have been thrown out and have been collecting in the ditch over the past eight months. I want to use the 18 gallon kitchen trash bags to collect. I called the recycling place closest to me, about 15 miles away, and they said they are paying $0.60 a pound for aluminum cans. I hope that is enough information, and we're broker than broke and need all the money we can get.

So my questions are:

  1. How much can I realistically carry inside my Ford Explorer

  2. How much does a bag of cans weigh if they are intact and not crushed (this place doesn't accept crushed cans because they are harder to cube)

  3. What the profit is per bag overall

  4. Using the profit per bag and carrying capacity of my car, what the profit is for the low end and high end gas price?

I'm sorry this if this is too much to really work on. I'm just very desperate right now.


r/theydidthemath • • 1d ago

[Request] My friend asked if an object 7.5x the Mass of Earth could replace Jupiter and still hold it's largest moons, and I set out to do the math. Can anyone here smarter than me point out if there's anything wrong?

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6 Upvotes

This assumes this object remains the same velocity and is in the same position that Jupiter was in. This also assumes it will keep the same orbit as well. Also sorry for the terrible handwriting.


r/theydidthemath • • 2d ago

[Off-site] I will be infinitely rich in ∞ years!

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2.1k Upvotes

@GLabsPlus on Twitter (X) calculates the total amount of money you can get if you were to receive the amount specified by that term of the harmonic series every minute.


r/theydidthemath • • 2d ago

[REQUEST] How much money could you reasonably make every day donating blood and still live a healthy life?

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956 Upvotes

r/theydidthemath • • 2d ago

[Request] : how large would a building have to be before the curvature of the earth would have to be taken into account during design and construction?

194 Upvotes

There’s a big warehouse/fulfillment center thing being built near my house and every time i drive past it I think about how the curvature of the earth must be measurable across it, though obviously only in millimeters so it wouldn’t impact design or construction. How big would a building have to be to have to take it into account?


r/theydidthemath • • 1d ago

[Request] What is the size of the trolls in this Swedish children song?

8 Upvotes

Translated it goes like this:

Once there was an ugly, old and wicked troll,
who came to this country in a hot-air balloon.
He settled down in Småland,
with his head on Åland,
and his feet, at the very same time, in Lund.
And the old troll had a troll wife, too.
Her nose was as big as all of Amsterdam.
She cooked up the food
and served it on plates,
a cake made out of sand,
as big as all of Svealand.
And the old troll had an old tomcat,
who was as big as the whole Kattegat.
Far away in Yokohama,
you could hear him yowling,
and his tail was as round
as the whole Öresund.
And so this little tale ends for now,
for the trolls have already left in their balloon.
Now they must be near the North Pole,
or perhaps right in the middle of the Sun.
And dear friend,
they'll never come back again.

I can see that the geographic references is both here and there but could the size of the trolls be decided?


r/theydidthemath • • 19h ago

[Request] What are the chances of this happening?

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0 Upvotes

Curious if this is as unlikely as it seems at first glance.

Had repost to fix the tag.


r/theydidthemath • • 18h ago

[Request] my friend's sister is 10 years younger than me, how many years i have to wait for her to become as old as me given that i travel at 0.99 speed of light

0 Upvotes

r/theydidthemath • • 15h ago

[Request] Roadster: Is this even possible?

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0 Upvotes

r/theydidthemath • • 1d ago

[Request] What percent grade is the incline?

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23 Upvotes

r/theydidthemath • • 1d ago

[request] Downforce to lift a 2 ton car

0 Upvotes

The rocket has massive thrust generated by fuel to lift it off. If the Tesla roadster thrust is purely generated by air and electricity how much energy is needed to lift the car like how it was shown in the demo? How much air will it take to lift it up?


r/theydidthemath • • 2d ago

[Request] Is coal waste really that radioactive?

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111 Upvotes

Sounds extreme when compared to actual nuclear energy


r/theydidthemath • • 1d ago

[Request] if the powerball lottery was hidden in a building instead, what are the equivalents of guessing the right building/home?

0 Upvotes

For example, getting 1 red powerball number gets you 4$, a 1 in 38 chance

The buildings are something close to

100 million single family homes (SFH).

5.2 million multifamily residential buildings (everything from duplexes to large high rises), containing 40 million housing units.

5.5 million commercial buildings.

350,000 industrial buildings.

240,000 military buildings.

So the question is, what powerball odds are equivalent to things like “guessing the right state” or “guessing the right street” or “guessing the right county”


r/theydidthemath • • 2d ago

[Request] How hot would the surrounding air and rock Frodo and Sam are on be with all that lava from Mount Doom be? Lord of the Rings Return of the King.

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369 Upvotes

Something I’ve always wondered was could people actually survive being on that rock with all that lava spilling down the mountain side? From what I see lava can be anywhere from 1300 degrees Fahrenheit to 2200, I mean that’s hot right? I’d expect the heat to rise up and warm the air around them and even more so the lavas heat would conduct through the rock they’re on and burn them. Could they even breathe the air? I know it’s fantasy and all but let’s put people in that exact scenario in real life.


r/theydidthemath • • 1d ago

[Request] In Ghosts (USA), can we calculate the average rate of death and average time spent as ghosts?

2 Upvotes

We know that about 5% of deaths result in a ghost, and that ghosts haunt the place they died for some time before moving to the great beyond.

At the time of the show, the haunted house features ghosts with the following death dates that have not yet moved on: 1007, 1513, 1777, 1891, 1895, 1928, 1950, 1969, 1985, 1987, 2000. There are also two groups of ghosts we could include, but who would dominate the data: 1777x3, 1832-1870x11.

Assuming a normal distribution, can we deduce how often new ghosts appear and how often they move on?


r/theydidthemath • • 2d ago

[Other] is this even possible? If yes how hard do you need to yeet the fly?

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123 Upvotes

r/theydidthemath • • 1d ago

How much thrust you would need to launch 1700kgs or 3700 pounds that high into the air? [request]

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1 Upvotes

Saw this request by someone in this post. Does it work?


r/theydidthemath • • 2d ago

[Request] Torque produced by these girls?

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52 Upvotes

Or like the centripital force or whatever force doing round and round produces?

If they have the average female weight.


r/theydidthemath • • 1d ago

[Request] Is it possible to calculate how far the quake would be felt if it was in fact a 9.9 earthquake and not 6.9? What about how big the tsunami triggered by this would be? How far the water would reach?

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2 Upvotes

r/theydidthemath • • 1d ago

[Other] Do a slice of bread and a slice of toast have any difference in nutritional value?

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0 Upvotes

An admirable commitment to the question!


r/theydidthemath • • 3d ago

[Request] how strong would Spider-Man's web have to be to block a shot from Elektra's rifle?

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3.2k Upvotes