Calculating the Sun's Power Output

[Jtappan]

Homework Statement

The Sun emits electromagnetic waves (including light) equally in all directions. The intensity of the waves at the Earth's upper atmosphere is 1.4 kW/m2. At what rate does the Sun emit electromagnetic waves? (In other words, what is the power output?)
____ W

Homework Equations

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The Attempt at a Solution

I have no idea how to do this one...

I know it involves I = P/A

 

[Shooting Star]

If r is the dist of Earth from sun, then total energy W emitted by sun in one second will fall on the surface of a sphere of radius r in one second (after 8.3 mins or so).

W/(4*pi*r^2) = 1.4*10^3 (given). You have to plug in the value of r in meters. That's all.