Note that the x$10$ closeup means that a reading $($in meters$)$ really is in tenths of meters.

For Animation $1,$ if you double the length, what happens to the change in length?

Repeat $($a$)$ for the material in Animation $2.$ How do the two results compare?

How does changing the final temperature change the expansion? $($If you double the change in temperature, what happens to the change in length?$)$

What general expression can you now write for the change in length as a function of the temperature change and initial length?