Uranus is 20 times farther from the Sun than is the Earth.How many times brighter does the Sun appear from Earth than from Uranus?
A)20 times
B)400 times
C)40 times
D)8000 times

Question

Quizplus · Accepted Answer

The brightness of the Sun decreases with the square of the distance. Since Uranus is 20 times farther from the Sun than Earth, the Sun appears 20^2 = 400 times brighter from Earth than from Uranus.

Uranus Is 20 Times Farther from the Sun Than Is