4. Earth is in thermal equilibrium. This means that our planet is radiating away exactly as much energy as it is receiving from
the Sun. This "re-radiation" from the Earth is not visible because it its peak wavelength is in the infrared part of the spectrum. Even the coldest parts of the Earth are way above absolute zero, so every square meter of Earth’s surface is radiating this energy out to space. Using the same radius given in step 2 above, and the formula for the area of a sphere, calculate the surface area of the Earth.
Earth is in thermal equilibrium. This means that our planet is radiating away exactly as much energy as it is receiving from the Sun. This "re-radiation" from the Earth is not visible because it its peak wavelength is in the infrared part of the spectrum. Even the coldest parts of the Earth are way above absolute zero, so every square meter of Earth’s surface is radiating this energy out to space. Using the same radius given in step 2 above, and the formula for the area of a sphere, calculate the surface area of the Earth.
(The radius of the Earth is 6,370,000 meters.)
The earth is spherical in shape , so we use the formula for finding the surface area of a sphere
