Steel ring fitting onto aluminum rod through thermal expansion

[queennicolee]

Homework Statement

A steel ring with a hole having area of 3.990 cm2 is to be placed on an aluminum rod with crosssectional area of 4.000 cm2. Both rod and ring are initially at a temperature of 35.0°C. At what common temperature can the steel ring be slipped onto one end of the aluminum rod?

Homework Equations

delta A = yAodelaT

T = To + deltaT

The Attempt at a Solution

 

[ubergewehr273]

Please show an attempt that you made at solving the problem.