What is the length of an aluminum rod at 65 C if it's length at 15 C is 1.2 meters?

Hi,

The thermal expansion coefficient for Aluminum is 2.31 x 10^-5,
referred to as alpha (or a below).

The formula for linear expansion of solids is
\delta L = aL\delta T
   = 2.31 x 10^-5 * 1.2m * (65C-15C)
   =0.001386m

This is the amount by which the length increases, which is very small
compared to 1.2 meters.  The new length would be 1.201386m



Here's a description of a lab on thermal expansion, with equations:
http://phoenix.phys.clemson.edu/labs/223/expansion/

Here's a page about Aluminum, along with physical constants:
http://www.efunda.com/materials/elements/element_info.cfm?Element_ID=Al

Here is a page describing thermal expansion:
http://irc.swan.ac.uk/ThExpansion.htm

             -welte-ga

Thank you very much you were very helpful, I am very grateful!!!!