A Circular Window in the Wall of a Home Has

A circular window in the wall of a home has a diameter of 25 cm and is made of a single pane of glass 0.30 cm thick. The thermal conductivity for the glass is 0.63 W/(m·K) . What heat is lost through the window in 12 s if the temperature inside the house is 20 °C and outside is −12 °C?

A) 16 kJ
B) 4.0 kJ
C) 1.6 kJ
D) 1.3 kJ
E) 5.0 kJ