Change in temperature and length problem help

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Homework Help Overview

The problem involves thermal expansion, specifically comparing the lengths of a lead rod and a glass rod as they are subjected to temperature changes. The original poster seeks to determine the temperature required for the glass rod to match the length of the heated lead rod.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • The original poster attempts to apply the thermal expansion formula but is uncertain about how to equate the changes in length for both materials. Participants inquire about the coefficients of thermal expansion for lead and glass and suggest writing a thermal expansion equation for the glass rod.

Discussion Status

The discussion is ongoing, with participants exploring the relationships between the materials' properties and their thermal expansion. There is a focus on understanding how to set up the equations correctly, but no consensus has been reached on the approach to take.

Contextual Notes

Participants note the need for specific constants related to thermal expansion, which may not have been provided in the original problem statement. The original poster expresses uncertainty about the variables needed for the solution.

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Lead rod and glass rod have same length at 20.8 degrees celsius. The lead rod is heated to 53.4 degrees celsius. At what temperature must the glass be heated so they are the same length?

I know that (change in L)/Lo = (alpha)(change in Temperature)

but I am not sure how to set (change in L of lead) = (change in L of glass) and i don't know what variables to use to solve for T of glass.

Can anyone help me get started on this one. Much appreciated!
 
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What is alpha for lead and glass? Can you write a thermal expansion equation for the glass rod?
 
they are just some constants...but i don't know how to set these to equations equal to each other to start the problem...
 
Why can't you just set them equal?
 

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