Poker Forum

Over 1,246,000 Posts!

Subscribe to FTR web feed
Already Registered?      Username:    Password:   Remember      Forgot Password
  >    > 

Simple (edit: Thermal) Physics Question

  
 
LinkBack Thread Tools Display Modes
kingnat
Old 10-24-2007, 12:41 PM     Post subject: Simple (edit: Thermal) Physics Question #1 (permalink)  
kingnat's Avatar
Full House

Join Date: Jun 2005
Posts: 827
kingnat is an unknown quantity at this point
Given the level of discussion Boost's post received I'd thought I'd throw another interesting question out there. It should be most interesting if people attempted to answer the question immediately after reading before checking out everyone else's reply... but I doubt many will do that.

This is not meant to have tricky language, so feel free to ask questions if you are confused. This is a physics question, so assume everything is ideal and such...

An ideal gas of temperature T, volume V, and pressure P, is inside a piston which is surrounded by an insulating jacket, and placed vertically on a table, (such that the piston head could move vertically). The frictionless piston head of mass M is free to move, but initially is at rest at a height H above the table. Slowly, a large number of small masses (considerably smaller than M) are added to the piston head.

Describe what happens to the gas after the masses are added, specifically whether the temperature, volume, and pressure increase, decrease, remain the same, or if there is not enough information given to determine the answer.
So you click their picture and then you get their money?
 
Reply With Quote
Join the FTR Poker Forum to disable these banners and start posting!
a500lbgorilla
Old 10-24-2007, 01:04 PM #2 (permalink)  
a500lbgorilla's Avatar
JESUS TAKE THE KEYBOARD

Join Date: Sep 2004
Location: This room is a good place to be
Posts: 8,379
a500lbgorilla is a name known to alla500lbgorilla is a name known to alla500lbgorilla is a name known to alla500lbgorilla is a name known to alla500lbgorilla is a name known to alla500lbgorilla is a name known to all
Send a message via AIM to a500lbgorilla
This is a thermodynamics problem, not a simple physics problem.

Smithers, use the amnesia ray.
You mean the revolver, sir?
Precisely.
 
Reply With Quote
kingnat
Old 10-24-2007, 01:07 PM #3 (permalink)  
kingnat's Avatar
Full House

Join Date: Jun 2005
Posts: 827
kingnat is an unknown quantity at this point
Quote:
Originally Posted by a500lbgorilla
This is a thermodynamics problem, not a simple physics problem.
What's not simple about thermo?
So you click their picture and then you get their money?
 
Reply With Quote
a500lbgorilla
Old 10-24-2007, 01:11 PM #4 (permalink)  
a500lbgorilla's Avatar
JESUS TAKE THE KEYBOARD

Join Date: Sep 2004
Location: This room is a good place to be
Posts: 8,379
a500lbgorilla is a name known to alla500lbgorilla is a name known to alla500lbgorilla is a name known to alla500lbgorilla is a name known to alla500lbgorilla is a name known to alla500lbgorilla is a name known to all
Send a message via AIM to a500lbgorilla
Quote:
Originally Posted by kingnat
Quote:
Originally Posted by a500lbgorilla
This is a thermodynamics problem, not a simple physics problem.
What's not simple about thermo?
Trying to call me out? I'm not very good at thermo unless it's applied to a compressible flow

Smithers, use the amnesia ray.
You mean the revolver, sir?
Precisely.
 
Reply With Quote
kingnat
Old 10-24-2007, 01:20 PM #5 (permalink)  
kingnat's Avatar
Full House

Join Date: Jun 2005
Posts: 827
kingnat is an unknown quantity at this point
Quote:
Originally Posted by a500lbgorilla
Quote:
Originally Posted by kingnat
Quote:
Originally Posted by a500lbgorilla
This is a thermodynamics problem, not a simple physics problem.
What's not simple about thermo?
Trying to call me out? I'm not very good at thermo unless it's applied to a compressible flow
Not in the least... I don't know squat about compressible flow... if anyone ever asks me a question about a real system I'm lost. Most physics folk treat thermo like the red-headed step-child of statistical mechanics, so much so that many schools are shifting away from teaching thermodynamics at the upper-level (or at least highly limiting it) in favor of more stat mech. I don't agree with that, but that's what's happening.... does this mean you aren't going to answer my question?
So you click their picture and then you get their money?
 
Reply With Quote
a500lbgorilla
Old 10-24-2007, 01:29 PM #6 (permalink)  
a500lbgorilla's Avatar
JESUS TAKE THE KEYBOARD

Join Date: Sep 2004
Location: This room is a good place to be
Posts: 8,379
a500lbgorilla is a name known to alla500lbgorilla is a name known to alla500lbgorilla is a name known to alla500lbgorilla is a name known to alla500lbgorilla is a name known to alla500lbgorilla is a name known to all
Send a message via AIM to a500lbgorilla
Anyway, here's my guess.

So balancing the forces you get (Internal - Ambient)*Area = M*g and ambient is considered constant. To increase M means you must increase P.

According to PV=RT, this is done either through decreasing volume or increasing T. To decide which it is, we must consult some laws.

The 1st law involves enthalpy which involves temperature. I don't know if I remember it exactly, but here goes.

I believe its Win - Qout = h2 - h1 = something.

The Qout is zero because it is an insulated piston. However, there is boundary pressure work being done. Work is a N*m, pressure being a N/m^2 says I probably need to multiply (Internal - Ambient)*Area*Distance Compressed. Which indicates a volume change will probably occur. Also, the work into the system will be positive so the volume will decrease. I guess Area*dheight is a dVolume? So the boundary work is PdV.

So PdV = h2 - h1 = cp(T2 - T1)? So for a dV to occur, a temperature change must occur. The left hand side is positive for this equation so T2-T1 > 0, suggesting temperature increases.

So as you add mass, the volume decreases, pressure increases and temperature increases.

EDIT maybe I should check the 2nd law to see if one of those remains constant. It's an isentropic process so ds = 0. Lemme think.

EDIT EDIT and where is this temperature increase coming from? Energy of the system remains constant. Well, I guess the energy of the system will change. The piston has some potential energy which is altered for a kinetic energy which will be passed into the fluid before equilibrium is reached again.

I'm gonna check out my book to remind me the 2nd law.

Smithers, use the amnesia ray.
You mean the revolver, sir?
Precisely.
 
Reply With Quote
spoonitnow
Old 10-24-2007, 01:34 PM #7 (permalink)  
spoonitnow's Avatar
Straight Flush

Join Date: Sep 2005
Location: IRC Chat Room
Posts: 5,406
spoonitnow is on a distinguished road
Send a message via AIM to spoonitnow Send a message via MSN to spoonitnow Send a message via Yahoo to spoonitnow Send a message via Skype™ to spoonitnow
rilla = mr physics ldo
Quote:
Originally Posted by Ripptyde
I only have 2 simple rules when I am coaching a new student.

Rule # 1: don't ask questions

Rule # 2: don't ask questions

I have no interest in discussing strategy with a protege'. Your job is to remain quiet and listen. I have a very systematic approach that I will share with the right candidate and I promise that I will turn you into a force of nature and show you elements of the game of poker that you never knew existed.
 
Reply With Quote
a500lbgorilla
Old 10-24-2007, 01:42 PM #8 (permalink)  
a500lbgorilla's Avatar
JESUS TAKE THE KEYBOARD

Join Date: Sep 2004
Location: This room is a good place to be
Posts: 8,379
a500lbgorilla is a name known to alla500lbgorilla is a name known to alla500lbgorilla is a name known to alla500lbgorilla is a name known to alla500lbgorilla is a name known to alla500lbgorilla is a name known to all
Send a message via AIM to a500lbgorilla
yah, I dont see anything about the 2nd law that would help. I'm satisfied with my answer.

Smithers, use the amnesia ray.
You mean the revolver, sir?
Precisely.
 
Reply With Quote
Jibalob
Old 10-24-2007, 01:58 PM #9 (permalink)  
Jibalob's Avatar
Flush

Join Date: May 2007
Location: Out of my roll
Posts: 512
Jibalob
Quote:
Originally Posted by a500lbgorilla
So as you add mass, the volume decreases, pressure increases and temperature increases
This is pretty basic knowledge, why all the formulae and laws?
PLEASE READ ULTIMATE BET THREAD IN "ONLINE POKER ROOMS" FORUM
Wait, this is .05/.10 and you got sexied, I can't believe that shit, limit must really be dying.[/quote]
 
Reply With Quote
a500lbgorilla
Old 10-24-2007, 02:13 PM #10 (permalink)  
a500lbgorilla's Avatar
JESUS TAKE THE KEYBOARD

Join Date: Sep 2004
Location: This room is a good place to be
Posts: 8,379
a500lbgorilla is a name known to alla500lbgorilla is a name known to alla500lbgorilla is a name known to alla500lbgorilla is a name known to alla500lbgorilla is a name known to alla500lbgorilla is a name known to all
Send a message via AIM to a500lbgorilla
Quote:
Originally Posted by Jibalob
Quote:
Originally Posted by a500lbgorilla
So as you add mass, the volume decreases, pressure increases and temperature increases
This is pretty basic knowledge, why all the formulae and laws?
So that I know why it will happen. Understand the process and everything will fall in line.

Also I don't have a very good internal model for temperatures, so anytime temps are added I have a little trouble working them through in my head.

EDIT and my way, you could predict the magnitudes of change for each of the variables.

Smithers, use the amnesia ray.
You mean the revolver, sir?
Precisely.
 
Reply With Quote
Warpe
Old 10-24-2007, 03:24 PM #11 (permalink)  
Warpe's Avatar
Moderator

Join Date: Sep 2005
Location: Canuckistan
Posts: 3,905
Warpe is a jewel in the roughWarpe is a jewel in the roughWarpe is a jewel in the roughWarpe is a jewel in the rough
Volume decreases and pressure increases, and both will remain at their new level. Temperature increases but will decrease again to reach equilibrium with its surroundings unless the insulating jacket is a perfect insulator (not enough information given).
 
Reply With Quote
Reply
Latest Poker News
KoRnholio Old 05-26-2012, 03:08 PM    Australia Legalized Online Poker coming up in next 6 to 12 Months
According to an email sent out by Mark Bryan, a gaming analyst at Merrill Lynch, the Australian government plans to legalize online poker sometime in the next six to 12 months. This move will coincide ...

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT. The time now is 12:22 AM.


FTR Testimonials

All content
© FlopTurnRiver.com
Advertising  |   Partners  |   Testimonials  |   T&C  |   Contact Us  |   FTR News & Press  |   Site Map  |   Search FTR

Full Tilt  |   Titan Poker  |   UltimateBet  |   Poker Stars  |   Ladbrokes Bonus  |   Sportsbook  |   Cake Poker  

Play Texas Holdem Online, Online Texas Holdem Strategy, & Poker Forum
This is not a gambling website.