Linear Thermal Expansion

Question

A brass bar and the aluminum bar are each attached to an immovable wall. At 25°C the air gap between the rods is 1.90x10^-3 m. At what temperature will the gap be closed?

Answer 1

The geometry is not at all clear so we can't answer the question.

Also, you haven't even given us the sizes of the bars, and coefficients of thermal expansion are in percents per degree not absolute distance per degree.

http://en.wikipedia.org/wiki/Coefficient...