Determine the heat-transfer rate per square meter of wall area for the case of a furnace with inside air at 1340 k. the furnace wall is composed of a 0.106-m layer of fireclay brick and a 0.635-cm thickness of mild steel on its outside surface. heat transfer coefficients on inside and outside wall surfaces are 5110 and 45 w/m2 ? k, respectively; outside air is at 295 k. what will be the temperatures at each surface and at the brick-steel interface?

the answer is f1 and d2 because if you put equal force on those two points the beam would balance trust me on this

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.