Question

Estimate the average power output of the Sun, given that

about1350W/m2 reaches the upper atmosphere of theEarth.
This distance from the Sun to the Earth is 1.5
x1011m.

Answer 1

Intensity is defined to be the power per unit area carried by a wave. Power is the rate at which energy is transferred by the wave. In equation form, intensity I is

I=\frac{P}{A}

Where P is the power through an area A.

Rearranging to find the Power we have that,

P = IA

The value of the given area for land can be approximated to that of a sphere, therefore the Area would be equivalent to

`A = 4\pi r^2`

Where r represents the distance from the sun to the earth.

Replacing with our values we have that

`P = (1350W/m^2)(4\pi r^2)`

`P =1350*(4\pi (1.5*10^(11))^2)`

`P = 38151*10^(22) W`

Therefore the average power output of the sun is
`P = 38151*10^(22) W`