How Does Temperature Affect the Movement of Mercury in a Thermometer?

Click For Summary
SUMMARY

The discussion focuses on calculating the movement of mercury in a Pyrex glass thermometer as temperature changes from 10.5°C to 33.0°C. The relevant coefficients for thermal expansion are provided: αPYREX = 3 × 10-6 (°C)-1, βPYREX = 9 × 10-6 (°C)-1, and βMERCURY = 180 × 10-6 (°C)-1. The volume change of the mercury bulb is calculated using the formula ∆V = β(V0)∆T, while the change in length of the mercury column is approached through the equation ∆L = α(L0)∆T. The participant seeks guidance on determining the coefficients for their proposed equation for the change in length of the mercury column.

PREREQUISITES
  • Understanding of thermal expansion coefficients (α and β).
  • Familiarity with the properties of mercury and Pyrex glass.
  • Knowledge of volume and length change equations in thermodynamics.
  • Basic algebra for manipulating equations and solving for unknowns.
NEXT STEPS
  • Research the derivation of thermal expansion formulas for liquids and solids.
  • Study the specific heat capacity and thermal conductivity of mercury.
  • Explore the design and calibration of thermometers using mercury.
  • Learn about the implications of thermal expansion in various scientific applications.
USEFUL FOR

Students studying thermodynamics, physics enthusiasts, and professionals involved in designing temperature measurement devices, particularly those using mercury thermometers.

Kingrly
Messages
1
Reaction score
0

Homework Statement


(a) The tube of a mercury thermometer (made of Pyrex glass) has an inside diameter of 0.140 mm. The bulb has a volume of 0.275 cm3. How far will the thread of mercury move when the temperature changes from 10.5 degrees Celsius to 33.0 degrees Celsius?

(b) Determine a formula for the change in length of the mercury column in terms of relevant variables. Ignore tube volume compared to bulb volume.

αPYREX = 3 × 10-6 (Degrees Celsius)-1
βPYREX = 9 × 10-6 (Degrees Celsius)-1
βMERCURY = 180 × 10-6 (Degrees Celsius)-1

Homework Equations


(I) ∆V = β(V0)∆T
(II) ∆L = α(L0)∆T

The Attempt at a Solution


I calculated the change in the volume of the bulb via equation I, but I am unsure where to head from here. Without knowing the height of the mercury within the thermometer (save for the temperature intervals), I am unsure of how to find the change in volume of the tube or the change in volume of the mercury itself. Any hints?
 
Last edited:
Physics news on Phys.org
For (b), I was thinking of an equation in the form of:∆L = mα(L0)∆T + nβ(V0)∆TWhere m and n are coefficients to be determined. Is this a valid approach?
 

Similar threads

Thermodynamics of mercury thermometers
  • · Replies 2 ·
Replies
2
Views
2K
Thermal Physics Expansion Coefficient Problem
  • · Replies 13 ·
Replies
13
Views
21K
Volume Expansion: Answers to Homework Questions
  • · Replies 3 ·
Replies
3
Views
12K
How to solve for the spillover for a spherical container?o
  • · Replies 12 ·
Replies
12
Views
2K
Expansion of mercury in a thermometer
  • · Replies 3 ·
Replies
3
Views
2K
Problem involving mercury thermometer
  • · Replies 1 ·
Replies
1
Views
6K
Calculating Final Pressure for a Metal Undergoing Temperature and Volume Changes
  • · Replies 1 ·
Replies
1
Views
2K
How Does Mercury Expansion in a Thermometer Relate to Temperature Changes?
  • · Replies 3 ·
Replies
3
Views
2K
How Do You Solve Adiabatic Expansion Problems in Thermodynamics?
  • · Replies 5 ·
Replies
5
Views
3K
Finding Increse in Volume Given Temp, Vol Expansion....
  • · Replies 8 ·
Replies
8
Views
5K