The intensity of sunlight falling on the earth is about 1.4 kW/m2 (before any gets absorbed by our atmosphere). At what rate does the sun emit light energy? (The earth-sun distance = 1.5 × 10⁸ km and the earth's radius = 6.4 × 10³ km.) A) 4.0 × 10²⁶ W B) 3.2 × 10²² W C) 7.2 × 10¹⁴ W D) 7.6 × 10⁸ W

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Quizplus · Accepted Answer

The sun emits energy uniformly in all directions. The intensity at the Earth's distance is 1.4 kW/m². The surface area of a sphere with a radius equal to the Earth-Sun distance is 4π(1.5 × 10^11 m)². Multiplying the intensity by this area gives the total power output of the sun, which is approximately 4.0 × 10^26 W.

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