The basal metabolism of a human adult is the total rate of energy production when a person is not performing significant physical activity. It has a value around 125 W, most of which is lost by heat conduction to the surrounding air and especially to the exhaled air that was warmed while inside the lungs. Given this energy production rate, it would seem impossible for a human body to radiate 460 W as you calculated in the previous part. Which of the following alternatives seems to best explain this conundrum?

a. The human body is quite reflective in the infrared part of the spectrum (where it radiates) so is in fact less than 0.1.
b. The surrounding room is near the temperature of the body and radiates nearly the same power into the body.

b.The surrounding room is near the temperature of the body and radiates nearly the same power into the body.

Explanation:

The human body typically have

absorption bands in the infrared part of the spectrum where room temperature objects radiate thermal energy. Also, the human skin has a high emissivity in this part of the spectrum.

i would like to make dinner for my mom, dad, and sister

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.