A Granite Wall Has a Thickness of 0

Multiple Choice

A granite wall has a thickness of 0.50 m and a thermal conductivity of 2.1 W/(m · C°) . The temperature on one face of the wall is 5.2 °C and 20.0 °C on the opposite face. How much heat is transferred in one hour through each square meter of the granite wall?

A) 2.2 × 10⁵ J/m²
B) 1.7 × 10⁵ J/m²
C) 7.4 × 10⁴ J/m²
D) 1.1 × 10⁶ J/m²
E) 62 J/m²