How Much Coffee Spills From a Heated Beaker?

  • Thread starter Thread starter owura143
  • Start date Start date
  • Tags Tags
    Heat Urgent
Click For Summary

Homework Help Overview

The discussion revolves around a physics problem involving the thermal expansion of coffee in a heated beaker. The original poster attempts to calculate the volume of coffee that spills from the beaker as its temperature increases from 20°C to 92°C, using the coefficient of volume expansion for water.

Discussion Character

  • Exploratory, Assumption checking, Conceptual clarification

Approaches and Questions Raised

  • Participants discuss the application of the coefficient of volume expansion and question the correctness of the original poster's calculations. There are inquiries about the units of the coefficient and its relevance to linear versus volume expansion.

Discussion Status

Participants are actively engaging with the problem, questioning assumptions about the coefficient of volume expansion and discussing its variability with temperature. Some guidance is offered regarding the potential need for an intermediate temperature to improve accuracy, but no consensus on the correct answer has been reached.

Contextual Notes

There is a mention of the need to report the answer in cubic meters, and some participants express uncertainty about the values used for the coefficient of volume expansion.

owura143
Messages
12
Reaction score
0
Urgent help need.Please ! Heat question

1. During an all-night cram session, a student heats up a one-half liter (0.50 10-3 m3) glass (Pyrex) beaker of cold coffee. Initially, the temperature is 20°C, and the beaker is filled to the brim. A short time later when the student returns, the temperature has risen to 92°C. The coefficient of volume expansion of coffee is the same as that of water. How much coffee (in cubic meters) has spilled out of the beaker?



Coefficient of volume expansion for water is 207 x 10^-6

I used the equation

delta V = beta x volume x delta T

= 207x10^-6 X 0.5x10^-3 X 72

= 7.452 X 10 ^-6


But the answer is wrong
 
Physics news on Phys.org
what are the units of beta?
 
That looks fine to me. What's the answer supposed to be?
 
The unit is 1/ degrees celsius.





i don't know the right answer
 
Ok. Are you sure that isn't a coefficient of linear expansion? Sorry, but I can't check for you right now.
 
water has no coefficient of linera expansion
 
that seems wrong, volume or sg changes by a couple of percent over the range mentioned.
 
Last edited:
my bad it asks to be reported in cubic meters. I get the same answer.
 
Last edited:
Where did you get your value for beta from?
 
  • #10
Hage, I looked it up as well, was 0.00021 on Wiki iirc.
 
  • #11
denverdoc said:
Hage, I looked it up as well, was 0.00021 on Wiki iirc.

I finally got out from under internet blockages as well, and I notice that that is correct at 20 degrees, but it's over 3 times larger at 90 degrees. Perhaps, choosing an intermediate temperature would give you a better approximation.
 
  • #12
Dick said:
I finally got out from under internet blockages as well, and I notice that that is correct at 20 degrees, but it's over 3 times larger at 90 degrees. Perhaps, choosing an intermediate temperature would give you a better approximation.

Yes, I found that too. I was wondering if the value was stated in the text somewhere or if the OP looked it up.
 

Similar threads

Having trouble with this one anyone can give some insight?
  • · Replies 3 ·
Replies
3
Views
2K
How Does the Heat Transfer Rate Affect a Beaker of Liquid Nitrogen?
  • · Replies 3 ·
Replies
3
Views
2K
Coeff. of Linear Exp. of glass from vol expansion of content
  • · Replies 6 ·
Replies
6
Views
8K
Amount of water spilled when the temperature is changed
  • · Replies 9 ·
Replies
9
Views
3K
Calculating Energy and Mass in Espresso Machine and Analyzing Cooling of Coffee
  • · Replies 33 ·
2
Replies
33
Views
8K
Heating 5.0dl of Coffee Water: How long does it take?
  • · Replies 4 ·
Replies
4
Views
2K
Thermal Expansion-how much has the ocean expanded
  • · Replies 3 ·
Replies
3
Views
2K
Another problem on Thermal Expansion
  • · Replies 5 ·
Replies
5
Views
5K
Urgent! Max Heat Withdrawn from Low-Temp Reservoir
  • · Replies 2 ·
Replies
2
Views
2K
Help with a volume expansion problem
  • · Replies 3 ·
Replies
3
Views
7K