Explanation:
Given that,
Average power of sun [tex]P=3.79\times10^{26}\ Watt[/tex]
We need to calculate the intensity of light at Earth's position
Using formula of intensity
[tex]I=\dfrac{P_{avg}}{4\pi r^2}[/tex]
Where, I = intensity
P = power
Put the value into the formula
[tex]I=\dfrac{3.79\times10^{26}}{4\pi\times(1.496\times10^{11})^2}[/tex]
[tex]I=1347.616\ W/m^2[/tex]
So, The intensity is 1347.616 W/m².
(A). We need to calculate the pressure on a solar sail due to the light of the sun if it's fully reflective
Using formula for fully reflective
[tex]P = \dfrac{2I}{c}[/tex]
Put the value into the formula
[tex]P=\dfrac{2\times1347.616}{3\times10^{8}}[/tex]
[tex]P=8.984\times10^{-6}\ N/m[/tex]
(B). We need to calculate the pressure on a solar sail due to the light of the sun if it's fully reflective
Using formula for fully absorptive
[tex]P=\dfrac{I}{c}[/tex]
[tex]P=\dfrac{1347.616}{3\times10^{8}}[/tex]
[tex]P=4.492\times10^{-6}\ N/m[/tex]
Hence, This is the required solution.