Asphere has radius 0.30 m, surface emissivity 0.48, and temperature 600 k. surrounding the sphere is a concentric spherical shell. the inner surface of the shell has radius 0.90 m, emissivity 1.00, and temperature 400 k. at what net rate and direction is heat radiated across the space between the sphere and the shell? the stefan-boltzmann constant is 5.67 × 10-8 w/(m2 ∙ k4). 18.8 kw, outward 10.8 kw, inward 8.3 kw, outward 6.5 kw, inward 4.0 kw, outward

what question you dont ask a question

explanation:

it has to be b, about 97 percent.

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.