# Problem: The intensity of sunlight at the Earth's distance from the Sun is 1370 W/m2. (a) Assume the Earth absorbs all the sunlight incident upon it. Find the total force the Sun exerts on the Earth due to radiation pressure.(b) Explain how this force compares with the Sun's gravitational attraction.Strength______________ times stronger.

###### FREE Expert Solution

The force exerted by the sun on the earth due to radiation pressure is:

$\overline{){{\mathbf{F}}}_{\mathbf{r}\mathbf{a}\mathbf{d}}{\mathbf{=}}\frac{\mathbf{I}\mathbf{A}}{\mathbf{c}}}$, where I is the intensity of light, A is the area (A = πR2), and c is the speed of light in a vacuum.

The gravitational force on earth:

$\overline{){{\mathbf{F}}}_{{\mathbf{g}}}{\mathbf{=}}\frac{\mathbf{G}{\mathbf{M}}_{\mathbf{E}}{\mathbf{M}}_{\mathbf{S}}}{{\mathbf{R}}^{\mathbf{2}}}}$

###### Problem Details

The intensity of sunlight at the Earth's distance from the Sun is 1370 W/m2

(a) Assume the Earth absorbs all the sunlight incident upon it. Find the total force the Sun exerts on the Earth due to radiation pressure.

(b) Explain how this force compares with the Sun's gravitational attraction.

Strength______________ times stronger.