Which straw fills the cup first?

[Pony]

I see a lot of these online, this is the most difficult I've come across IMO. I think I know the answer.

We're a brighter than average bunch here, lets see if we can beat the 99.9% I believe got it wrong on Facebook.


https://i.imgur.com/uasaU68.jpg

[Pony]

My answer is:

3

[lost in melb.]

If the straws are blocked 6, if not, 2

[Pony]

If the straws are blocked 6, if not, 2

6 is blocked at the bottom. Why 2? (2 was the most common answer)

[DemonGeminiX]

Ok, so the lines crossing openings and joints are blocking the flow?

[DemonGeminiX]

Ok, so the lines crossing openings and joints are blocking the flow?

Ok, assuming this above:

6, 5, 4, and 3 are all blocked... actually, all of the standard flow points are blocked. The first apparent breach occurs right above the main-3 joint, so the fluid traveling downward will back up to that first breach, and following along that outer line leads to the liquid dropping into the 2 cup. So 2 will be filled first.

[Pony]

Ok, assuming this above:

6, 5, 4, and 3 are all blocked... actually, all of the standard flow points are blocked. The first apparent breach occurs right above the main-3 joint, so the fluid traveling downward will back up to that first breach, and following along that outer line leads to the liquid dropping into the 2 cup. So 2 will be filled first.

Assuming a liquid will flow along the top of a straw?

[Griffin]

6

[Pony]

6


6 is blocked at the bottom

[DemonGeminiX]

Assuming a liquid will flow along the top of a straw?

Good point. Ok, then it drips from the breach and falls between 3 and 4 and no cup gets filled at all.

[Pony]

Good point. Ok, then it drips from the breach and falls between 3 and 4 and no cup gets filled at all.

Most posts I saw said #2. I think there would be enough surface tension for the liquid to run down the underside of straw 3 into cup 3. What do you think?

[DemonGeminiX]

Most posts I saw said #2. I think there would be enough surface tension for the liquid to run down the underside of straw 3 into cup 3. What do you think?

I think, based on your surface tension argument, 2 gets some, 3 gets some more, and we can even assume that 4 gets some and 5 gets a drop or two by the Jeff Goldblum Jurassic Park Chaos Theory explanation, but if we're assuming typical fluid dynamics, then none gets filled completely and there's a clean up between cups 3 and 4. But if we're going by shitty android 2-dimensional game physics, then 2 gets filled.

[Pony]

:mrgreen:

[Pony]

I think, based on your surface tension argument, 2 gets some, 3 gets some more, and we can even assume that 4 gets some and 5 gets a drop or two by the Jeff Goldblum Jurassic Park Chaos Theory explanation, but if we're assuming typical fluid dynamics, then none gets filled completely and there's a clean up between cups 3 and 4. But if we're going by shitty android 2-dimensional game physics, then 2 gets filled.

If we calculate rate of pour vs the size of the openings into the mix, I think you may be right, the majority will likely end up everywhere but in the cups

[Griffin]

6 is blocked at the bottom

:meh:

[lost in melb.]

6 is blocked at the bottom. Why 2? (2 was the most common answer)

If all the blocks are real it must be 2 or 3. The liquid will flow out of the hole into either 2 or 3.

2 if the liquid flows quickly, like a waterfall.

3 if slowly and it hugs the outside of the straw :-k

[Teh One Who Knocks]

Is that an upside down menorah? :-s

[DemonGeminiX]

Is that an upside down menorah? :-s

:-s

Hannukah in July?

[Teh One Who Knocks]

Heresy! :x

[lost in melb.]

Is that an upside down menorah? :-s


:-s

Hannukah in July?

I can see my 13 years of University education has been for nothing :|

[Teh One Who Knocks]

I can see my 13 years of University education has been for nothing :|

Not my fault you aren't observant :hand:

[Godfather]

I'm not smart enough to follow the fluid dynamics line of thought, but does it not go:
- Path to 5 fills but is blocked.
- Path to 4 fills but is blocked.
- Path to 6 fills but is blocked.
- Path to 3 fills but is blocked.
- Water escapes and starts to fill 2.
- Water backs up to path to 7 but is blocked.
- Water fills to paths to 1 then 2 but is blocked.
- Water may back up to path that allows escape over to 1, but by then the path to 2 is still filling 2.
- Maybe there's a backup and water spills over the top to 7 and 1, but by then 2 has been filling the entire time

My vote is 2.

https://i.imgur.com/1lCyh09.png

[lost in melb.]

If all the blocks are real it must be 2 or 3. The liquid will flow out of the hole into either 2 or 3.

2 if the liquid flows quickly, like a waterfall.

3 if slowly and it hugs the outside of the straw :-k




I'm not smart enough to follow the fluid dynamics line of thought, but does it not go:
- Path to 5 fills but is blocked.
- Path to 4 fills but is blocked.
- Path to 6 fills but is blocked.
- Path to 3 fills but is blocked.
- Water escapes and starts to fill 2.
- Water backs up to path to 7 but is blocked.
- Water fills to paths to 1 then 2 but is blocked.
- Water may back up to path that allows escape over to 1, but by then the path to 2 is still filling 2.
- Maybe there's a backup and water spills over the top to 7 and 1, but by then 2 has been filling the entire time

My vote is 2.

https://i.imgur.com/1lCyh09.png

Professional diagram.

Or if filled slowly 3??

[Godfather]

There's a fairly large ledge to get over to drip back to #3.

Someone could build this thing in this free browser based fluid dynamics game, that would be funny but too time consuming for me :lol:

https://dan-ball.jp/en/javagame/dust2/

[Pony]

There's a fairly large ledge to get over to drip back to #3.

Someone could build this thing in this free browser based fluid dynamics game, that would be funny but too time consuming for me :lol:



You're assuming the liquid will run along the top of the straw? I think (if poured slowly) it would run down the underside of #2 straw and fill cup 3.

[Godfather]

You're assuming the liquid will run along the top of the straw? I think (if poured slowly) it would run down the underside of #2 straw and fill cup 3.

Sorry when I said to get back to #3 I meant #2, I don't think it can run backward enough to #2 to fill it before #3 is full. I tried the fluid dynamics game and tried to match the angle, I don't think much liquid will run back along the edge of the straw towards #2 at all.