Solve Enjoyable Enigmas with Mr.E's Challenge

[drizzle]

The blind man sings.. Loudly. :p

 

[Enigman]

The blind man sings.. Loudly. :p

He's deaf. Deaf people don't sing.

 

[consciousness]

Finer point about man crossing road-

Spoiler

I added the bit about the starlight to make the problem harder. Starlight does reach us during the day although it is overpowered by the sun.

Solve this one. It is kinda hard, but if you solve it you will feel really smart.(For a day that is )

Two identical spheres receive identical amounts of thermal energy, the heat transfer occurring so quickly that none is lost to the surroundings. If they begin at the same temperature, but one is on a table and the other is suspended by a string, will the spheres still have the same temperature immediately after the quick addition of thermal energy?

 

[collinsmark]

A physics enigma-

Two identical spheres receive identical amounts of thermal energy, the heat transfer occurring so quickly that none is lost to the surroundings. If they begin at the same temperature, but one is on a table and the other is suspended by a string, will the spheres still have the same temperature immediately after the quick addition of thermal energy?

Spoiler

Yes, they will have the same temperature immediately after the quick addition of thermal energy -- a transfer that was such that no heat was exchanged with the surrounding environment.

This assumes that the string and the table are part of the environment, and thus were not involved in any heat transfer. This includes any possible ionization effects: the string and table are part of the environment and were not affected by the heat transfer at all -- at least not yet.

This neglects any quantum effects of the different configurations, which wouldn't be measurable anyway if the spheres are at all larger than microscopic.

This also neglects any differences caused by general relativity (as opposed to Newtonian gravity), which wouldn't even come close to being measurable assuming the these are regular old objects, here on Earth.

And lastly it assumes that none of thermal energy is transferred to the surroundings via thermal vibrations -- again, no energy is transferred to the surroundings, and that includes the string and table.

Edit: Oh, and of course I don't mean that the spheres will have the same temperature that they started with. I mean they will have the same temperature as each other.

 

[collinsmark]

Two identical spheres receive identical amounts of thermal energy, the heat transfer occurring so quickly that none is lost to the surroundings. If they begin at the same temperature, but one is on a table and the other is suspended by a string, will the spheres still have the same temperature immediately after the quick addition of thermal energy?

Spoiler

Yes, they will have the same temperature immediately after the quick addition of thermal energy -- a transfer that was such that no heat was exchanged with the surrounding environment.

This assumes that the string and the table are part of the environment, and thus were not involved in any heat transfer. This includes any possible ionization effects: the string and table are part of the environment and were not affected by the heat transfer at all -- at least not yet.

This neglects any quantum effects of the different configurations, which wouldn't be measurable anyway if the spheres are at all larger than microscopic.

This also neglects any differences caused by general relativity (as opposed to Newtonian gravity), which wouldn't even come close to being measurable assuming the these are regular old objects, here on Earth.

And lastly it assumes that none of thermal energy is transferred to the surroundings via thermal vibrations -- again, no energy is transferred to the surroundings, and that includes the string and table.

Edit: Oh, and of course I don't mean that the spheres will have the same temperature that they started with. I mean they will have the same temperature as each other.

Spoiler

That last post also assumed that the two spheres were identical at the time the heat transfer, and at the time temperature measurements were taking place.

But now I think I see where this riddle is going.

I think the riddle meant to say, "the spheres are not ideal sphere's. Instead they are practical spheres that are not completely rigid. And they are identical before being placed on the string or the table, but not necessarily after."

If that were the case then the sphere hanging on the string would tend to "stretch out" ever so slightly, while the sphere on the table would tend to compress upon itself every so slightly. Thus the spheres wouldn't technically be identical anymore at the time they were hanging from a string or sitting on a table.

In that case, the sphere on the table would be slightly denser, containing a slightly larger energy density, and be slightly hotter.

 

[consciousness]

collinsmark, this is a very practical riddle. Nowhere in the problem statement have the spheres been called "ideal". You have to take practical considerations into mind while solving this one. You are on the right track, almost.

Spoiler

I don't understand the last part about compression though. Why would it compress? I think you are ignoring a very practical consideration here.

 

[zoobyshoe]

I have not been contributing enough riddles, so I went to the library today and got a book.

Here's one:

"An ordinary cyclist travels up and down a hill. Going up, she maintains a constant speed of 10 mph. It takes her 1 hour to get to the top. Assuming the hill is symmetric, what speed must she maintain on the way going down if she wishes to average 20 mph?"

 

[drizzle]

Spoiler

∞?

 

[Office_Shredder]

consciousness, I have trouble reconciling "two identical spheres" and "these spheres are not perfect spheres".

 

[zoobyshoe]

Your light switch is on the other side of the room from your bed. However, you make a bet that you can turn the light off and jump in bed before the room gets dark. No timers are involved. How do you win this bet without violating SR?

 

[zoobyshoe]

Boomerang Ball:

You throw a ball as hard as you can. It doesn't hit anything, and no strings or rubber bands are attached to it, yet, it comes right back to you. How can this be?

 

[zoobyshoe]

You are standing on a hard concrete floor and you have no cushioning to use. You bet someone you can drop a raw egg 4 feet without it breaking. You promise you won't even drop it on your feet. How do you win this bet?

 

[drizzle]

Boomerang Ball:

You throw a ball as hard as you can. It doesn't hit anything, and no strings or rubber bands are attached to it, yet, it comes right back to you. How can this be?

Spoiler

Is there not a word for 'vertical relative to Earth's surface'? In my language there's vertical, and there's this word which means vertical relative to Earth's surface..

 

[Enigman]

Spoiler

Is there not a word for 'vertical relative to Earth's surface'? In my language there's vertical, and there's this word which means vertical relative to Earth's surface..

Spoiler

...Up?

 

[drizzle]

Lol

 

[zoobyshoe]

Spoiler

Is there not a word for 'vertical relative to Earth's surface'? In my language there's vertical, and there's this word which means vertical relative to Earth's surface..

Spoiler

In physics any line that is perpendicular to a given surface is "normal" to that surface. The word "up" would have done just fine, though I wish it hadn't been blurted out without spoilers.

 

[Enigman]

I have not been contributing enough riddles, so I went to the library today and got a book.

Here's one:

"An ordinary cyclist travels up and down a hill. Going up, she maintains a constant speed of 10 mph. It takes her 1 hour to get to the top. Assuming the hill is symmetric, what speed must she maintain on the way going down if she wishes to average 20 mph?"

Spoiler

teleportation allowed?

Your light switch is on the other side of the room from your bed. However, you make a bet that you can turn the light off and jump in bed before the room gets dark. No timers are involved. How do you win this bet without violating SR?

Spoiler

use a torch? It was a day?

You are standing on a hard concrete floor and you have no cushioning to use. You bet someone you can drop a raw egg 4 feet without it breaking. You promise you won't even drop it on your feet. How do you win this bet?

Spoiler

Er, catch it before it falls?

 

[consciousness]

My question was somewhat ambiguous. I have edited it now.

Two identical metal spheres receive identical amounts of thermal energy, the heat transfer occurring so quickly that none is lost to the surroundings. If they begin at the same temperature, but one is on a table and the other is suspended by a string, will the spheres still have the same temperature immediately after the quick addition of thermal energy?

I have another answer for raw egg-

Spoiler

Concrete floors aren't so easily broken!

Cyclist-

Spoiler

Its not possible!

Hint for spheres-

Spoiler

Metals appreciably expand on heating

 

[collinsmark]

My question was somewhat ambiguous. I have edited it now.

Two identical metal spheres receive identical amounts of thermal energy, the heat transfer occurring so quickly that none is lost to the surroundings. If they begin at the same temperature, but one is on a table and the other is suspended by a string, will the spheres still have the same temperature immediately after the quick addition of thermal energy?
[...]
Hint for spheres-

Spoiler

Metals appreciably expand on heating

Spoiler

Assuming now that both spheres maintain identical densities with respect to each other, and have positive thermal expansion coefficients (unlike zirconium tungstate), then the sphere on the string will be the hotter of the two.

Conservation of energy is at play here. The average height of the sphere on the table will rise up a bit, while the sphere on the string will be lowered. The difference in potential energy equates to work done by a heat engine, essentially. The end result is, for the moment at least, the sphere that gains potential energy is the colder of the two, meaning that the sphere on the string is hotter than the one on that table, since the sphere on the string lost potential energy and the sphere on the table gained potential energy in the process.

 

[consciousness]

Spoiler

Assuming now that both spheres maintain identical densities with respect to each other, and have positive thermal expansion coefficients (unlike zirconium tungstate), then the sphere on the string will be the hotter of the two.

Conservation of energy is at play here. The average height of the sphere on the table will rise up a bit, while the sphere on the string will be lowered. The difference in potential energy equates to work done by a heat engine, essentially. The end result is, for the moment at least, the sphere that gains potential energy is the colder of the two, meaning that the sphere on the string is hotter than the one on that table, since the sphere on the string lost potential energy and the sphere on the table gained potential energy in the process.

Correct.

 

[collinsmark]

Here's one that I made up myself, many years ago.

You work at a pawn shop. Some guy comes in and wants to pawn off an old war medal.

He says, "This is my great grand-dad's medal that he got in World War I. And it's a really special medal too; it was made with a personal inscription when he got it, by a General! This has got to be worth a lot!"

You look over the medal. It's a circular medal with an eagle on the front of it. On the back of it you can read the inscription,

Sergeant Smith,
Thank you for your courage
and bravery in World War I.

-General Jones,
April 20, 1917​

You don't know how much to give him for the medal, so you ask you manager (the owner of the pawn shop) to take a look at it. He looks it over for a moment, and says to the man, "This is worthless. I'm not giving you a cent for this." And the man takes the medal back and walks out of the shop.

Why did your manager say it's worthless?

--------------------

Just to answer some of the more low-hanging-fruit questions:

You ask your manager, "did WWI medals not have eagles on them?"
He replies, "I really don't know. Could be. The truth is I really don't know much about WWI medals, or even WWI in general. You would think I would, owning a pawn shop and all. But the truth is I don't. It's not my area of expertise," he pauses, "but I know that was fake."

You ask your manager, "did WWI medals not have inscriptions on them?"
He replies again, "I really don't know. Maybe so, maybe not. -- That one was fake though."

You ask your manager, "was there not a General Jones in WWI?"
He says, "I really don't know. Like I said, I don't know a whole lot about WWI."

[Edit: Corrected spelling of "Sergeant."]

 

[Enigman]

I know this one...the one I read was about a sword not a medal though.

 

[zoobyshoe]

Spoiler

teleportation allowed?

Spoiler

Right idea

Spoiler

use a torch? It was a day?

Spoiler

both correct

Spoiler

Er, catch it before it falls?

Spoiler

This is correct, but there's another different solution.

 

[zoobyshoe]

I have another answer for raw egg-

Spoiler

Concrete floors aren't so easily broken!

Correct. But there's yet another solution.

Cyclist-

Spoiler

Its not possible!

Spoiler

Yes, best answer.

 

[zoobyshoe]

Spoiler

∞?

Spoiler

right idea

 

[Enigman]

You are standing on a hard concrete floor and you have no cushioning to use. You bet someone you can drop a raw egg 4 feet without it breaking. You promise you won't even drop it on your feet. How do you win this bet?

Spoiler

Drop the egg on the feet of the person you made the bet with? Depending on his reflexes he might catch it or else well, some things are worth losing a bet for...

 

[consciousness]

Another answer to raw egg-

Spoiler

I thought about the possibility of hard raw eggs and the ostrich came to mind. The trick is to procure an ostrich egg (from some where!). You can can throw it on concrete and it probably won't break. Apparently it requires a hammer and a drill to break!

 

[Office_Shredder]

For the WW1 puzzle:

Spoiler

Is it because sergeant is spelled incorrectly, or was that just a mistake in the typing of the puzzle? Alternatively, that date is only two weeks after the US declared war, so it seems possible that no US troops had actually seen combat by that point (I admit I had to google when the US entered to confirm this)

 

[Enigman]

For the WW1 puzzle:

Spoiler

Is it because sergeant is spelled incorrectly, or was that just a mistake in the typing of the puzzle? Alternatively, that date is only two weeks after the US declared war, so it seems possible that no US troops had actually seen combat by that point (I admit I had to google when the US entered to confirm this)

No.
(collinsmark isn't online now so I am taking the liberty to answer for him. Sorry, collinsmark.)

 

[Office_Shredder]

WW1 solution:

Spoiler

Oh, obviously it was called world war 1 until after world war 2 started.