What is the intensity of sunlight per square meter reaching Venus compared with this intensity at Earth's orbital distance? (For orbital radii,see Appendix,Table C-1,Comins,Discovering the Essential Universe,6th ed.)
A) about the same, since this intensity remains constant, following a law of nature
B) about 1.4
C) about 1.9
D) about 0.5

Question

Quizplus · Accepted Answer

Venus has an average distance from the Sun of 0.72 AU, while Earth has an average distance of 1.00 AU. According to the inverse square law of radiation, the intensity of sunlight per square meter decreases with the square of the distance from the Sun. Using the ratio of distances squared (0.72/1)^2, the intensity of sunlight reaching Venus is about 1.9 times greater than the intensity at Earth's orbital distance. Therefore, the correct answer is C, about 1.9.

What Is the Intensity of Sunlight Per Square Meter Reaching