Question

Find the intensity of electromagnetic radiation at the surface of the sun (radius r=R=6.96×105kmr=R=6.96×105km). Ignore any scattering of the waves as they move radially outward from the center of the sun.

Answer 1

Answer:

$I = 4.46*10^{16}W/m^2$.

Explanation:

Intensity $I$ of the electromagnetic radiation is given by

$I = \dfrac{P}{4\pi r^2},$

where $r$ is the distance from the EM source (the center of the sun, in our case), and $P$ is the power output of the sun and it has the value

$P = 3.9 *10^{26}W.$

Since the radius of the sun in meters is $r = 6.96*10^8km$, the intensity $I$ of the electromagnetic radiation at the surface of the sun is

$I = \dfrac{3.9*10^{26}W}{4\pi (6.96*10^8m)^2}\\\\\boxed{ I = 4.46*10^{16}W/m^2}$

The intensity of the electromagnetic radiation at the surface of the sun is $I = 4.46*10^{16}W/m^2$.