The emissivity of tungsten is $0.350$. A tungsten sphere with radius $1.50$ cm is suspended within a large evacuated enclosure whose walls are at $290.0$ K. What power input is required to maintain the sphere at $3000.0$ K if heat conduction along the supports is ignored?

An electric kitchen range has a total wall area of $1.40$ m² and is insulated with a layer of fiberglass $4.00$ cm thick. The inside surface of the fiberglass has a temperature of $175$°C, and its outside surface is at $35.0$°C. The fiberglass has a thermal conductivity of $0.040W/m\cdot K$. What is the heat current through the insulation, assuming it may be treated as a flat slab with an area of $1.40$ m² ?

A carpenter builds an exterior house wall with a layer of wood $3.0$ cm thick on the outside and a layer of Styrofoam insulation $2.2$ cm thick on the inside wall surface. The wood has $k=0.080W/m\cdot K$ , and the Styrofoam has $k=0.027W/m\cdot K$. The interior surface temperature is $19.0$°C, and the exterior surface temperature is $-10.0$°C. What is the temperature at the plane where the wood meets the Styrofoam?

A carpenter builds an exterior house wall with a layer of wood $3.0$ cm thick on the outside and a layer of Styrofoam insulation $2.2$ cm thick on the inside wall surface. The wood has $k=0.080\,W/m\(\cdot\) K$ , and the Styrofoam has $k=0.027\,W/m\(\cdot\) K$. The interior surface temperature is $19.0$°C, and the exterior surface temperature is $-10.0$°C. What is the rate of heat flow per square meter through this wall?