Go Back   Physics Help Forum > High School and Pre-University Physics Help > Thermodynamics and Fluid Mechanics

Thermodynamics and Fluid Mechanics Thermodynamics and Fluid Mechanics Physics Help Forum

Like Tree1Likes
Reply
 
LinkBack Thread Tools Display Modes
Old Mar 4th 2018, 03:20 PM   #1
Member
 
Join Date: Mar 2013
Posts: 32
Heat

In a thermally insulated environment, there is water with a mass of 200 gr at 20 degrees Centigrate.We drop 60 grams of ice into the water with a temperature of -40 degrees. If thermal equilibrium is maintained find the mass of ice and water in the environment?

I found the answer as:

60.0.5.10+m80=200.1.20
m of ice=35 and mass of water is 225.
According to tthe book answer is 25 and 235.

Last edited by kastamonu; Mar 7th 2018 at 07:53 AM.
kastamonu is offline   Reply With Quote
Old Mar 4th 2018, 06:17 PM   #2
Senior Member
 
Join Date: Apr 2017
Posts: 290
how can there be 225 or 235 gm of water at the end , when to start you have 20gm of water and 60 gm of ice????
oz93666 is offline   Reply With Quote
Old Mar 5th 2018, 04:57 AM   #3
Senior Member
 
Woody's Avatar
 
Join Date: Jun 2016
Location: England
Posts: 470
It looks to me like a miss-typing
it must be 200g of Water at 20C + 60g of ice at -40C

I don't understand your notation:
60.0.5.10+m80=200.1.20
are you using the "." as a multiplication symbol?
are you using the "." as a decimal place?
are you using it as both?
or something different?

As a programmer, I find the use of "*" quite natural for a multiplication symbol,
but this is personal preference.
It matters little as long as it is clear what convention is being employed.

The inclusion of brackets can (hugely) improve the readability of equations.
__________________
~\o/~
Woody is offline   Reply With Quote
Old Mar 5th 2018, 11:36 AM   #4
Senior Member
 
Join Date: Jun 2010
Location: NC
Posts: 386
Solid-Liquid Equilibration

Here's are two similar situations solved by thermo.
Citrus Concentrate | THERMO Spoken Here!

For the rifle musket, upon impact, the loss of kinetic energy causes the
Minie ball to become liquid, partially.
Springfield Rifle Musket (1861) | THERMO Spoken Here!

good luck, TSH
THERMO Spoken Here is offline   Reply With Quote
Old Mar 6th 2018, 02:02 PM   #5
Member
 
Join Date: Mar 2013
Posts: 32
. is for multiplication and , for decimal place. Mass of water is 200 gr.

Last edited by kastamonu; Mar 6th 2018 at 02:21 PM.
kastamonu is offline   Reply With Quote
Old Mar 6th 2018, 02:03 PM   #6
Member
 
Join Date: Mar 2013
Posts: 32
Originally Posted by THERMO Spoken Here View Post
Here's are two similar situations solved by thermo.
Citrus Concentrate | THERMO Spoken Here!

For the rifle musket, upon impact, the loss of kinetic energy causes the
Minie ball to become liquid, partially.
Springfield Rifle Musket (1861) | THERMO Spoken Here!

good luck, TSH
Is there an answer for my question?
kastamonu is offline   Reply With Quote
Old Mar 6th 2018, 02:07 PM   #7
Member
 
Join Date: Mar 2013
Posts: 32
Originally Posted by oz93666 View Post
how can there be 225 or 235 gm of water at the end , when to start you have 20gm of water and 60 gm of ice????
Where is my mistake? Is my answer right or wrong?

Last edited by kastamonu; Mar 6th 2018 at 02:23 PM.
kastamonu is offline   Reply With Quote
Old Mar 7th 2018, 05:00 AM   #8
Senior Member
 
Join Date: Aug 2010
Posts: 320
The point is that mass is conserved. If you started with 200g of water and 60 gm of ice, so you have 260 g all together, then, no matter how much ice melts or water freezes you end with a total of 260 g, not "225 g" or "235 g".
HallsofIvy is offline   Reply With Quote
Old Mar 7th 2018, 07:56 AM   #9
Member
 
Join Date: Mar 2013
Posts: 32
But there will be ice and water in the end. The problem asks the amount of ice and water seperately. In the end sum will be 260. But how much of this 260 will be ice and how much will be water?
kastamonu is offline   Reply With Quote
Old Mar 12th 2018, 03:35 AM   #10
Junior Member
 
Join Date: Feb 2018
Posts: 4
Hi, firstly we need to know how much latent heat of melting of ice to water is required. It is also to know how much heat is available due to differences of temperature of ice and water. It's seem from the equation not all ice is melted even after equilibrium temperature is achieved and therefore having both ice and water at equilibrium temperature.
Heat balance equation is required to know the equilibrium temperature. Well understood that heat will flow from water to ice. So the temperature of water is decreases while of ice increases. But since total ice is not melted. So it is also possible to use 0 degree temperature as equilibrium temperature. It's my thought
pmahajan18 is offline   Reply With Quote
Reply

  Physics Help Forum > High School and Pre-University Physics Help > Thermodynamics and Fluid Mechanics

Tags
heat



Thread Tools
Display Modes


Similar Physics Forum Discussions
Thread Thread Starter Forum Replies Last Post
Specific latent heat and heat capacity Punch Thermodynamics and Fluid Mechanics 0 Apr 23rd 2010 06:51 PM
Specific heat / heat capacity help!! joannahector1225 Thermodynamics and Fluid Mechanics 0 Mar 6th 2010 06:48 PM
Heat h_mprince Thermodynamics and Fluid Mechanics 1 Sep 8th 2009 12:14 AM
heat honkydora Thermodynamics and Fluid Mechanics 1 Nov 29th 2008 08:30 PM
Heat mikeportnoy Thermodynamics and Fluid Mechanics 1 Oct 6th 2008 08:19 PM


Facebook Twitter Google+ RSS Feed