Intensity: 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 rate at which the sun emits light energy can be calculated by considering the intensity of sunlight at the Earth's distance and the surface area of a sphere with a radius equal to the Earth-Sun distance. The intensity of sunlight is given as 1.4 kW/m^2. The surface area of a sphere is 4πr^2, where r is the Earth-Sun distance (1.5 × 10^11 m). Thus, the total power output of the sun is 1.4 kW/m^2 * 4π(1.5 × 10^11 m)^2 = 4.0 × 10^26 W.

Intensity: the Intensity of Sunlight Falling on the Earth Is