# Thermal expansion and coefficient of linear expansion

at 20C a rod is exactly 20.05cm long on a steel ruler. Both the rod and the ruler are placed in an oven at 270C, where the rod now measures 20.11cm on the same ruler. What is the coefficient of linear expansion for the material of which the rod is made?

## Homework Equations

$$\Delta$$L=L$$\alpha$$$$\Delta$$T
L(i)rod=20.05cm
L(f)rod=20.11
L(i)steel=20.05 ??
$$\Delta$$T=250C
$$\alpha$$steel=11 x 10^-6

## The Attempt at a Solution

Ls=20.05cm(11x10^-6)(250C)
L=.055cm

I don't know what to do now-