Two asteroids have identical masses. However, one asteroid is twice as far from the Sun than the other. According to Newton's Universal Law of Gravitation the force of gravity exerted by the Sun on the more distant asteroid is
A) the same size as the force exerted on the closer asteroid
B) one-quarter of the size of the force exerted on the closer asteroid
C) twice as large as the force exerted on the closer asteroid
D) one-half of the size of the force exerted on the closer asteroid

Question

Quizplus · Accepted Answer

According to Newton's Universal Law of Gravitation, the force of gravity between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. Since the two asteroids have identical masses, the force of gravity exerted by the Sun on each asteroid is directly proportional to the square of the distance between them. Therefore, if one asteroid is twice as far from the Sun than the other, the force of gravity exerted by the Sun on the more distant asteroid is one-quarter (2^(-2)) of the size of the force exerted on the closer asteroid. Thus, the correct answer is B) one-quarter of the size of the force exerted on the closer asteroid.

Two Asteroids Have Identical Masses