Science IQ Test

[Hoodat]

__________________________

The Overcrowded Prison

A prison was overcrowded, and the warden decided to release a prisoner by giving a test.
He had three prisoners brought to his office and explained his proposition.

"The guard behind you has a duffel bag with  5 hats in it.  Three are black and two are red.
He will place one hat on each of you from behind you.  If you can tell me the color of your hat, you will be released to go home.  But you must agree not to guess and if you guess wrong, you understand you will be shot immediately.  Agreed?" 
[No lose proposition.  All agree.  Hats are placed on the three.]
First prisoner looks at other two:  "I don't know."
Second prisoner looks at other two:  "I don't know."
Third prisoner is blind: "I know."

Does he or doesn't he?  Explain or you will be shot.

First Prisoner:  The only way he could know the color of his own hat is if Prisoner 2 and Prisoner 3 were both wearing red.  Since he didn't know, then either Prisoner 2 or Prisoner 3 (or both) was wearing a black hat.

Second Prisoner:  Realizing that either he or Prisoner 3 must be wearing a black hat, if he sees a red hat on Prisoner 3, then he knows he must have a black hat on.  Since he doesn't know, then Prisoner 3 can't be wearing a red hat.

Third Prisoner:  Without seeing the hats of Prisoners 1 and 2, he knows he has on a black hat.

[Hoodat]

Science IQ Test Number Four

Will a container of pure, distilled water freeze into solid ice at exactly zero degrees Celsius and standard pressure (760 Torr)?

No.  It will remain liquid water at 0°C and 1 atm.

[ChemEngrMBA]

No.  It will remain liquid water at 0°C and 1 atm.

Hoodat so smart he got everthang ko-rect.
In the same way, a container of ice will remain ice at 0 degrees. In my first chemistry class in high school, I wondered how water can freeze at 0 while ice melts at 0.
That may be the defined freezing point, but if you look at a graph of the triple point, you see lines where two phases are at perfect equilibrium and at that one point, all three phases.
Steam isn't always hot.  At extremely low pressure it can be colder than your freezer.

http://Water-Wow.blogspot.com

[ChemEngrMBA]

Science IQ Test #5

Why shouldn't you wear sunglasses while playing tennis, or paddleball?

P.S.  This board is on a weird time zone I tell you.  It's like Greenwich Mean Time.

[ChemEngrMBA]

Science IQ Test #5

Why shouldn't you wear sunglasses while playing tennis, or paddleball?

Nobody knows?    I posed this question last year to my late good tennis buddy, Dr. Ken, who was an eye surgeon.  He replied, "I don't see any reason why sunglasses would do that."
But a retired air force pilot told me it was the case.
I said to the eye surgeon, "Let's think about this.  Sunglasses cause your pupils to dilate.
This reduces the depth of field (span of feet, front to back, where everything is in focus) in your eyes."

That is the definition of depth perception being reduced.  Dr. Ken had to agree with me because it is so obvious.

Now you know.

[Hoodat]

So if you drop acid before playing tennis, your depth perception won't be as good?

[Elderberry]

So if you drop acid before playing tennis, your depth perception won't be as good?

Maybe not. But you won't care. You'll see wonderful traces following the ball.

[ChemEngrMBA]

So if you drop acid before playing tennis, your depth perception won't be as good?

How do you make the transition from being so smart to the opposite in just days?

[Elderberry]

Science IQ Test #5

P.S.  This board is on a weird time zone I tell you.  It's like Greenwich Mean Time.

https://www.gopbriefingroom.com/index.php/topic,447842.msg2491934.html#msg2491934

The forum time zone was recently updated to match that on our new server. For almost everyone, this causes times in articles and replies to display wrong. There is an easy fix, which is to update your profile to tell the forum software what time zone your in. To do this, Go here:

https://www.gopbriefingroom.com/index.php?action=profile;area=theme

Click on "(auto detect)" next to the Time Offset field.
Scroll down and click the "Change Profile" button.

[Hoodat]

How do you make the transition from being so smart to the opposite in just days?

It's a gift.

[Hoodat]

Andy, Bill, Chuck, and Dwight hold the professions of aviator, builder, cashier, and doctor, but not necessarily in that order.  Only the cashier tells the truth.  The other three professions always lie.

Here are three statements.  Use these to determine each person's profession:

Andy:  Bill is the cashier
Bill:  Chuck is not the doctor
Chuck:  Andy is the builder

[Elderberry]

Andy is the aviator
Bill is the builder
Chuck is the doctor
Dwight is the cashier

[DB]

Andy, Bill, Chuck, and Dwight hold the professions of aviator, builder, cashier, and doctor, but not necessarily in that order.  Only the cashier tells the truth.  The other three professions always lie.

Here are three statements.  Use these to determine each person's profession:

Andy:  Bill is the cashier
Bill:  Chuck is not the doctor
Chuck:  Andy is the builder

Andy is the Aviator.
Bill is the Builder.
Chuck is the Doctor.
Dwight is the Cashier.

[DB]

Andy is the aviator
Bill is the builder
Chuck is the doctor
Dwight is the cashier

Yep.

[DB]

Andy has to be lying because he'd have to be the cashier to be telling the truth.
Therefore Bill cannot be the cashier and what Bill says is a lie. Therefore Chuck has to be the doctor and is also lying.
Therefore Andy is not the builder, the doctor or the cashier leaving only the Aviator.
Bill has to be the builder because he is not the cashier, doctor or aviator.
With Andy, Bill and Chuck proven as liars only Dwight is left to be the cashier.

[ChemEngrMBA]

Science IQ Test #6

How much ice at 0 degrees Celsius will be required to cool one pound of gold at 100 degrees Celsius, just melting all of the ice so that both are at 0 degrees?

No calculations, please.  Guess.

(It is a wild and crezzy answer from a wild and crezzy guy.)

[Hoodat]

Off the top of my head, 80 cal per gram of ice, and approx 6°C of average metal per calorie, I would say each unit of ice can bring down 5 units of metal by 100 °C.  So around one-fifth lb of ice. or 0.44 kg.  But gold may not be your average metal.

[ChemEngrMBA]

Reasonable estimate. Not even close.  I doubt that anybody else can do better.
The answer is stunning due to two disparate factors which are force multipliers. (S.H. and H.O.F.)

[Hoodat]

You're right.  I was way off.

[DB]

Science IQ Test #6

How much ice at 0 degrees Celsius will be required to cool one pound of gold at 100 degrees Celsius, just melting all of the ice so that both are at 0 degrees?

No calculations, please.  Guess.

(It is a wild and crezzy answer from a wild and crezzy guy.)

Infinity.

[Smokin Joe]

Science IQ Test #6

How much ice at 0 degrees Celsius will be required to cool one pound of gold at 100 degrees Celsius, just melting all of the ice so that both are at 0 degrees?

No calculations, please.  Guess.

(It is a wild and crezzy answer from a wild and crezzy guy.)

None. Zero. Just stick it in a box and set it out on the step for a while. (current outdoor ambient temp is 12 above)

[DB]

None. Zero. Just stick it in a box and set it out on the step for a while. (current outdoor ambient temp is 12 above)

I don't think he's after the practical answer...

Any energy added to any volume of exactly 0 C water will raise the temperature above 0 C and melt it. Using an infinite amount of water ice at 0 C will melt it but will be 1/infinity close to 0 C.

That's the theory I'm going with...

[Hoodat]

I don't think he's after the practical answer...

Any energy added to any volume of exactly 0 C water will raise the temperature above 0 C and melt it. Using an infinite amount of water ice at 0 C will melt it but will be 1/infinity close to 0 C.

That's the theory I'm going with...

The poster is using for heat of fusion for water.  The transition from one gram of ice at 0°C to one gram of water at 0°C releases 80 calories of heat (or 334 joules).  So you need to know roughly how much heat is needed to raise the temperature of one gram of gold by 100°C (which is where my guess of 16 cal fell apart).

[ChemEngrMBA]

The poster is using for heat of fusion for water.  The transition from one gram of ice at 0°C to one gram of water at 0°C releases 80 calories of heat (or 334 joules).  So you need to know roughly how much heat is needed to raise the temperature of one gram of gold by 100°C (which is where my guess of 16 cal fell apart).

Hoodat, Hoodat, Hoodat, what we gonna do wid choo? 

Ice melting to water ABSORBS 80 calories per gram, it doesn't "release" it.  Confusing words is easy when you know what you mean but misspeak.

Water holds 33 times as much heat as an equivalent weight of gold, and then multiply that by 80 for the heat of fusion. 

The answer is 0.617 ounces of ice.
 
Water has a heat capacity of 4.18 J/g C degree
Gold has a heat capacity of 0.129 J/g C degree
The heat of fusion of water is 80 times the heat capacity of water, so one gram of gold will cool down 100 degrees C with the loss of 12.9 Joules.  Ice will melt absorbing 4.18 J x 80 per gram or  334.4 J without changing temperature!
The ratio of 12.9 to 334.4 or .038576 will apply to any respective quantity of gold cooling 100 C and ice just melting without even changing temperature.  So a pound of gold at 100 C requires .038576 pound of ice at 0 to cool it.   .038576 of 16 ounces is 0.617 ounces of ice.

[Your estimate of .16 specific heat for gold was really good!  Only off by a factor of 2.]

[ChemEngrMBA]

Science IQ Test #7

How many ounces of steam at 100 degrees Celsius will heat up one pound of gold at 0 degrees Celsius, just condensing all the steam so that both are at 100 degrees Celsius?

The previous solution will guide you to a very close estimate!  Both answers are surprising and informative.  They show why our Brilliant Creator gave water its unusual properties, because we are 90% water, and it keeps us from freezing or dying of heat prostration easily.  Very cool.