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/sci/ - Science & Math

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5897576 No.5897576 [Reply] [Original]

<---------- Both are water. Both are equal amounts. One is poured into the other.

Find the temperate of the water in the final cup.

>> No.5897581

>>5897576

how much time passes before you measure the cup?

>> No.5897583

Need the air temperature, time passed, and air humidity if you want a good answer.

>> No.5897589

>>5897581
>>5897583

Use common sense and answer the question. You are free to print the picture out and use all scientific measurement tools at your disposal to test the picture for additional data if that's what's required to solve the problem.

>> No.5897591

>>5897576
Clearly 85 degrees. What is this, math for babbys?

>> No.5897593

>>5897591

Incorrect.

>> No.5897594

>>5897589

common sense says i mix them and wait an hour and come back and it's room temperature.

I could show you how the temperature changes with time though

>> No.5897604

>>5897583 is me

Read it again, there's no water in the final cup.

Hurf durf, word problems.

>> No.5897608

Clearly 170 degrees. What is this, math for babbys?

>> No.5897611

>>5897576
By equal amounts do you mean same volume at the time of taking the temperature or same volume when at the same temperature?

>> No.5897614

>>5897604

hurr durr " i say final, when i really mean empty"

pretty smart there

>> No.5897615

Need to know the calorimeter constant as well as time elapsed after mixing.

GG NO RM 2EZ

>> No.5897651

>>5897594

Applying an arbitrary amount of time isn't logical or common sense.

>> No.5897652

>>5897611

If I meant volume I'd have said volume. The data I wanted to offer is exact and intended.

>> No.5897657

So I used mc(120-t)=mc(50-t)
assuming no heat lost to surroundings
so then i divide by mc because they are both the same substance (c is same) and mass is the same (sorry if i confused anyone about this point).
but then the ts cancel out and im left with 0=70 which doesnt sound right...

>> No.5897662

>>5897604

Incorrect.

>> No.5897664

It's 70 degrees celcius

>> No.5897669

Assuming perfect efficiency, my immediate thought is that the temperature would be the average of their temperatures in Kelvin.

Is this right, or horribly wrong?

>> No.5897671

>>5897589
Common sense tells me you know nothing about thermodynamics.

>> No.5897677

>>5897669

no, because the two fluids don't mix evenly instantly, because of the temperature gradient, if you measure too soon, where you measure will determine what temp you get. if you wait a while for them to mix a bit, then it'll be slightly lower or higher than their average depending on the room temp

>> No.5897702

>>5897671

Incorrect, and complaining doesn't replace a valid solution.

>> No.5897705

>>5897669

If not stated, assume a common sense answer for any variable.

>> No.5897716

the answer to this question will inevitably depend on the substance itself. We need its specific heat, density, ect to accurately make an answer.

Your move OP

>> No.5897719

>120 degree water

>> No.5897720

>>5897576
(273+120+50+273)/2

>> No.5897722

Is this in Celsius or Fahrenheit?

>> No.5897723

>>5897719
Fahrenheit, dude.

>> No.5897725

>>5897723
why not mention it ?? Perhaps it's under high pressure...
If it's in F, then first convert it to K then do the average (because you mix the same amount ) and that's how you get the answer.

>> No.5897726

doesnt water absorb a lot a lot of energy to heat up? Would that mean that 70 degrees takes half the energy that 80 degrees takes? So if you mix the 120 and the 60 you wouldnt get 80 you would get something closer to 100 right?

non-precise answer

>> No.5897729

>>5897726
no, energy in water is directly proportional to the temperature

>> No.5897731

>>5897723

>imperial units

Disgusting

>> No.5897743

>>5897657
but the heat gained by the water at 50 is the same that the one lost by the water at 120, so it is (t-120) = -(t-50), isn't it?

>> No.5897769
File: 5 KB, 275x183, index.jpg [View same] [iqdb] [saucenao] [google]
5897769

>this thread

I know it must be a troll thread but
>same substance, same amount
>it not being obvious to take the average
>85

>> No.5897880

>>5897716

The substance is water. You don't need any more data than I've provided you with.

>> No.5897882

>>5897726

That is incorrect, but at least you're thinking.

Many people here aren't seeing the forest for the trees, and as such, they're overlooking something very important.

>> No.5897884

>>5897576
How the fuck do you have a liquid water with temperature of 120 degrees? What's the pressure like in there?

>> No.5897886

>>5897884
Using Celsius, I shig

>> No.5897888

120 water is less dense than 50 water so contains less atoms

mixture will be about 82

>> No.5897891

>>5897886
>Science
>Not using Celsius when it comes to fucking simplistic measurements

lel ur dum is kelvin so its 2 bloks of ice they cant mix fuk u my name is jon and i hate all of you

>> No.5897900

>>5897888
same amount = same number of moles = same number of atoms

>> No.5897911

then why not (120+50)/2 ?

>> No.5897915

>>5897911

You're missing the same thing everyone else is.

>> No.5897917

>>5897915
You have to also heat up the beaker at 50 degrees

>> No.5897953
File: 13 KB, 564x676, 1371843921172.png [View same] [iqdb] [saucenao] [google]
5897953

>>5897608

>> No.5897971

>using celsius
Fucking europeans.

>> No.5898018

The answer is 85 degrees, the problem is OP keeps saying it is wrong when it is 100% correct and people second guess themselves because they are idiots.

Hell you can prove it with energy conservation,
Energy in cup A+Energy in cup B= Energy in cup A+B. Suppose cup A and B have G grams, and Water is C Joules/(Fahrenheit*grams)
Then (120)*C*G+(50)*C*G=T*2C*G=>T=170/2=85.
Technically you are supposed to convert to kelvin but it works out the same because it's right. But yeah, answer is 85, anything but violates energy conservation.

>> No.5898024

(120+50)/2

>> No.5898026
File: 1017 KB, 665x663, happy holidays.png [View same] [iqdb] [saucenao] [google]
5898026

>>5897971
not sure if troll

>> No.5898043

>>5898018

There is something in the picture you're missing.

>> No.5898048

>>5898043
Nope, there really isn't. Either the answer is 85 degrees or you didn't give enough information.

>> No.5898077

>>5898048

You haven't reviewed the contents of the OP properly.

>> No.5898080

>something in the picture

can it be quantified or is it some sophistry?

>> No.5898084

>120 degrees
>'murrica with it's moronic system

>> No.5898096

50 degrees

>> No.5898099

>>5898080

Quantifiable and logical. The entire OP put together has something all of you are missing.

>> No.5898105

>common sense
>common sense

How about you stop being such an annoying douche ?

>> No.5898112

are we allowing for cooling during the pouring process? or have we moved into a reality this is not present?

>> No.5898113

OP says "amount," I think he means "volume." Hot water is less dense.

>> No.5898127

>>5898043
>>5898077
>>5898099

You are an asshat

>> No.5898137

Jesus I hate it when annoying dipshits come up with some stupid word problem just so they can yell YOURE WRONG at everyone and make themselves feel smart.

Why the fuck does this thread exist? Please kill yourself, OP.

>> No.5898140
File: 122 KB, 740x538, words_that_end_in_gry.png [View same] [iqdb] [saucenao] [google]
5898140

>>5897576
>temperate

>> No.5898162

>>5898113

It's not volume. I chose my words very.... very... carefully. This challenge is specifically geared towards /sci/'s tendency to overanalyze as well as its oversight of the most logical definitions and answers when searching for the perfect scientific parameters.

Funnily enough, the most certain of you are the most wrong. There have been 2 inquiring posters who are the two closest people in this thread, and one of them was kind of insulted/dismissed by other posters despite being the best candidate to solving this thing (imo). Neither, however, figured out a key detail between the text and the picture.

Proftip: It is not difficult, but it is also not a scientific study sheet. Science is not always conducted within the shelter of a bureaucratically predictable social system inside of a scientifically perfect lab. Sometimes the situation calls for you to just use your sense of logic and come up with the best answer you can.

It is fully acceptable for you to get it wrong once. Most people would. But I am 100% honest when I say incorrect. It's not a cheap trick, and it is based is either math, logic, or science. It is not a cheap word problem, but the statements as they are do matter in conjunction with the picture.

Obviously I am not here looking for advice; I am here to present a challenge to you. If someone solves it, I will ask them what their favorite trip is or name is on /sci/, and give them my complete grats... since I encountered this premise a month ago, and it took me 3 weeks to solve it.

>>5898127

Is your tripcode and inability to solve this problem supposed to mean something to me?

>> No.5898165

>>5897677

Perhaps, but you can't calculate any of that.

>> No.5898172

>>5898162
>Find the temperate of the water
>It's a trick question because I said temperate instead of temperature
No, you are just being a pretentious idiot. This isn't math or science related, this is just you being a retard.

>> No.5898177

>>5898162
If it's not a cheap trick, could you repeat the problem using far more words, and centrigrade/kelvin? Or would that give it away?

If explaining the problem properly gives it away, it's a cheap trick. The fact that you offer a minimal explanation is what makes people suspicious; solving the problem becomes irrelevant compared to working out what the problem actually is.

Look. If I go over to the kitchen right now, take equal masses of hot and cold water, measure their temperatures, then mix them and measure again, I expect to see the average of the temperatures. The fact that you insist this is incorrect for your puzzle merely shows that your puzzle isn't what it appears to be, because you're communicating badly, because that's the only way you have of feeling cleverer than the people who gave the obvious answer to what seemed like an obvious question.

People who did that, said 85 even in such an obvious Ruse Thread, good on you. That's the right way to live.

>> No.5898181

>>5897576
>Water
>120 degrees
>Not expressing temperature as Kelvin

>inb4 F
>inb4 high pressure environment

>> No.5898186

>>5897576
I like this. Not telling people that the cup on the left is actually steam.
The final temperature is 50 degrees.

>> No.5898188

>>5898186
Actually you did with the black lines. Hehehe.

>> No.5898191

>>5898186
>>5898188

What the fuck has it to do with science or logic?
It is just a trick question, abusing the fact that most peole will use common sense and assume that both glasses contain fluids.

>> No.5898197

>>5898191

Well it's not that unfair. He does say it's water, and the steam lines are very conspicious.

>> No.5898204

>>One is poured into the other.
regardless of steam or liquid this implies the action took place.

>> No.5898205

>>5898197
Then the graphic is flawed.
The steam wouldn't flow downwards as suggested with the third cup. The steam wouldn't remain in the bucket if it wasn't sealed off.

>> No.5898207

Trolled you all hard, not so smart now are you.

>> No.5898209

50° obviously, the water at 120° is steam

>> No.5898219

wouldn't the cup contain both temperatures until they finally equalised over time?

>> No.5898222

>>5898191
>assume both glasses contain fluids
>steam is not a fluid

>steam is a gas
>Gasses are liquids..
>checkmate scientists

>> No.5898223

>both are water

the cup must contain superheated water, not steam

>> No.5898303

>>5898177

Other than my typo of temperate (obviously temperature, but spellcheck screwed me over), everything is as intended, and all info is at it's intended limit.

Everything else, you need to use logic and common sense.

>> No.5898309

>>5898191

I have stated multiple times that the problem is not a trick. I have also stated multiple times that logic and common sense always prevail against the unknown variables.

If, after that, you believe it's steam, then there is most likely no chance that you will solve this problem.

>> No.5898322
File: 58 KB, 515x449, findtemp.png [View same] [iqdb] [saucenao] [google]
5898322

OP, FTFY

>> No.5898327

>>5898322
See:
>>5898303
For some reason he doesn't want to include units. Unless the 'degrees' is meant as in 'alternative to radians,' in which case... well, like the steam, that's another meaningless puzzle.

And yet he claims it's a logic puzzle. Ha. Ha.

>> No.5898330

>>5898322
M1CT1 = M2CT2
M1(T-T1) = M2(T2-T)
M1(50-T) = M2(T-10)
M1=M2
50-T = T-10
2T=60
T=30

>> No.5898332

http://vocaroo.com/i/s1vlL3UxBO3h

>> No.5898334

>>5898330

You're good. And motivated.

You're now my frontrunner to solve my problem.

>> No.5898340

The fact that the hot water is poured into the glass of cold water (from the picture) means the temperature will be below the average of the two, since the glass also be at the temperature of the water it contains and contribute to the decrease.

Something like that? I don't know how to get the actual number with that. Shrug.

>> No.5898346

It's obviously 120 and 50 because quantum shit
lol fucken retards /thread

>> No.5898355

50 Celsius or 120 Fahrenheit
Because there both the same temperature and you're a fucking moron who can't use consistent units.

>> No.5898357

Perhaps it's room temperature. There is a blue liquid and a red liquid which will mix to form a purple liquid, which is not the end product. We're left with black which, assuming we're not doing anything with, remains the same independent of the addition of the two separate cups.

>> No.5898359

God damn it will you idiots stop bumping this stupid thread. OP is trying to troll you all by saying everyone with the right answer is wrong and saying we are missing something that isn't there.

>> No.5898362
File: 34 KB, 217x255, 4901599786_f7da90a70a.jpg [View same] [iqdb] [saucenao] [google]
5898362

>>5898334
It's the average, the same thing we've been doing with the fucking OP post.

>> No.5898363

That was lame, OP.

>> No.5898364

>>5898177
This guy won the thread btw, delivering quite the pasta-worthy sermon.

>> No.5898369

>>5898362

You're no longer my frontrunner. You fell to the common mistake.

>> No.5898381

>>5898369
Was I on the right track here?

>>5898340

>> No.5898394
File: 49 KB, 515x449, 1373690044956.jpg [View same] [iqdb] [saucenao] [google]
5898394

>>5897576
Fix'd

>> No.5898396

>>5898394
HAH
>>5898369
Use the equation you complimented him for.
Plug in 120 and 50
get 85
simplified eqn comes out to Tf = (T1+T2)/2
Mistake

So what's the fucking answer, faggot?

>> No.5898400

Let the mass and temperature of cup 1 & 2 be denoted m1, T1 & m2, T2 respectively. When mixed together, let the temperature in the equilibrium state be denoted T. Let c denote the specific heat capacity of water.

The change in energy in cup 1 & 2 will be

delta-U1 = m1*c*(T-T1)
delta-U2 = m2*c*(T-T2)

Conservation of energy dictates that

delta-U1 = -delta-U2
m1*c*(T-T1) = m2*c*(T2-T)

Setting m1 = m2, we can rearrange and find that

m1*c*(T-T1) = m1*c*(T2-T)
T-T1 = T2-T
2T = T1+T2
T = (T1+T2)/2

Insert for T1 and T2.

>> No.5898401

>>5897581
>>5897583
>>5897589
>>5897591
>>5897593
>>5897594
>>5897604
>>5897608
>>5897611
>>5897615
>>5897651
>>5897652
>>5897657
>>5897662

FUCKING CHRIST

ITS THE AVERAGE OF THE TEMPERATURES.

>> No.5898435

LEL

>> No.5898439

KEK

>> No.5898442

LOL

>> No.5898447

Bump

>> No.5898451

>>5898447
pls stop rusing

>> No.5898455

What's the fucking answer op? Bumping until you tell us

>> No.5898458

What you mean? I not geniius.

>> No.5898462

>>5898458
If you gonna keep posting pls reply to this post so I can feel good with all responses thx
>>5898394

>> No.5898464

EK could have solved this but you asshats had to go and run her off.

>> No.5898469

>>5898394
>>5898462
FEEL BETTER?

>> No.5898476

Is it 1?

>> No.5898484

>>5898469
thx <3

>> No.5898478

Is it 2?

>> No.5898488

Is it 50?

>> No.5898490

Is it 51?

>> No.5898491

Is it 52?

>> No.5898492

Is it 53?

>> No.5898495

Is it 54?

>> No.5898496

Is it 55?

>> No.5898501

Is it 56?

>> No.5898505

>>5898501
Are you gonna do this until you reach 120? I'm not gonna stop you, I just want to know.

>> No.5898554

85.

>> No.5898740

I think I've got it. Since there's steam on the drawing it means the water is boiling. So the unit is °C and the cup is or was just in a pressurized environment which made its boiling temperature increase to 120°C. During and after the pouring, some of the steam will liquefy, releasing high amounts of energy, though obviously not enough for all the water to evaporate. In the end, there will be some amount of boiling water, different from the sum of the initial cups, but the temperature will be 100°C since it's boiling.

>> No.5898769

>>5898740
Well, let's try to say 75 degrees then.

>> No.5898778

>>5898554
Yes.

Fucking christ, this wasn't that hard.

>> No.5898781

This is clearly a troll image because water stops heating up at 100 degrees and then evaporates, staying at 100 for the whole time.

>> No.5898784

>>5898781
he never specified the temperature scale. they're obviously both in liquid phase, so it doesn't matter.
It's 85 degrees, regardless of OP's definition of a degree.

>> No.5898793

>>5898784
The annoying thing is that he keeps saying that 85 is wrong.

>> No.5898810

>>5898769
What I meant is that the answer was 100°C

>> No.5898823

Is it completely poured in?

i.e. the final cup contains the total of the 2 cups?

>> No.5898826

if there are the same amounts of water, the mixing temperatur is exactly (temp1+temp2)/2

>> No.5898836

It wouldn't exactly be the average of the 2, because assuming it is the volume that is equal, the heat capacity of water is different at different temperatures

>> No.5898842

Let's say this is a douchebag scenario. For instance, temperatures are in Celsius, and the first cup is mislabeled at the water level.

Since boiling water cannot exceed 100°C:
(100+50)/2 = 75

So, 75°C, if OP is a douchebag.

>> No.5898859

>>5897576
Assuming it is a closed system with no energy loss. 85 degrees.

>> No.5898947

so... where'd OP go?

>> No.5898966

>>5898947
He's too busy sucking cocks and not labeling units.

>> No.5899112

crudest diagram ever, labeled poorly, drawn by an aspie? or just a moron?

>> No.5899206

>>5898842
Pressure conditions were not specified. Your third sentence does not hold

>> No.5899541

>>5898396

I didn't compliment his equation. I just referred to him as my favorite to get it, but he gave up early.

>> No.5899767

>>5899541
Are you reading all of the posts or what?

>> No.5899909

>>5899112
I do not see anything wrong with it.

>> No.5899949

>>5898330
>>5898400
no body of you guys have heard of the fact that thermal capacity of water changes with temperature of the water?

so was OP making for the fact that you have to do some fancy integrations of sorts to get the result or what?

>> No.5900020

>>5899767

Yes, I'm reading all of them.