Finding loss of sun's mass given the energy density delivered.

[texan14]

Homework Statement

The energy density (energy per unit area per unit time) arriving from the sun at the surface of the Earth is 1300 J/m2s. Calculate the mass loss of the sun in one year. (The Earth is about 1.49 x 1011 m from the sun.)

Homework Equations

ΔE = Δmc²

KE = (γ-1)mc²

The Attempt at a Solution

I'm not sure how to calculate the loss of energy density from the sun as a function of distance. I feel like it can't be as easy as plugging the energy into E=mc²

 

[vela]

Hint: You're not given an energy; you're given an energy density.