Two identical silver spheres of mass m and radius r are placed a distance R (sphere 1) and 2R (sphere 2) from the Sun respectively.The ratio of the pressure of solar radiation on sphere 2 to that on sphere 1 is:
A)0.25.
B)0.50.
C)1.0.
D)2.0.
E)4.0.

Question

Quizplus · Accepted Answer

The pressure of solar radiation is inversely proportional to the square of the distance from the Sun. Therefore, the pressure on sphere 2, which is at a distance of 2R, is (1/2^2) = 1/4 times the pressure on sphere 1, which is at a distance of R. Hence, the ratio is 0.25.

Two Identical Silver Spheres of Mass M and Radius R