Seeking Appropriate Equation for Linear Conductivity

[enter8]

Homework Statement

I am attempting to calculate the approximate time it takes for a stone slab to fully preheat, focusing only on one dimensional steady flow conduction. Both my area and mass are unknown.

Thermal conductivity: 6.4 W/mK
Specific heat capacity: 0.98 J/gK
Density: 2,980 kg/m³

Thickness of slab: 3.18 cm
Distance to center: 1.59 cm
T1: 260 C.
T2 (core): 21.11 C.

Homework Equations

This is what I'm looking for.

The Attempt at a Solution

I've spent hours looking through textbooks trying to find the right equation, but everything I run across seems to have additional info such as area and mass.

 

[Andrew Mason]

You will have to give us the whole problem. Area and mass are needed but I suspect that they fall out in your calculation.

AM