The length of a steel beam increases by 0.78 mm when its temperature is raised from 22 degrees C to 35 degrees C. What is the length of the beam at 22 degrees C (in meters)?

1 Answer
Jun 21, 2015

l_0=4.545m
I may be wrong but I think you need something else...the expansion coefficient perhaps...?

Explanation:

You can use the expression that describes thermal linear expansion as:
Deltal=l_0alphaDeltaT
Where:
Deltal=l-l_0=change in length;
l_0=original length (at 22°C);
alpha=expansion coefficient;
DeltaT=change in temperature.
In your case:

0.78/1000=l_0*alpha*(35-22)

From the litterature you have:
http://dev.physicslab.org/PracticeProblems/Worksheets/APB/Heat/thermalexpansion.aspxhttp://dev.physicslab.org/PracticeProblems/Worksheets/APB/Heat/thermalexpansion.aspx

With the data you have and the coefficient from the table:
l_0=4.545m