Question

Pluto and its moon Charon are the closest in size and mass to any other orbiting bodies in our solar system. Charon is 1/2 the mass of Pluto and only about 12,000 miles apart, causing an extreme orbital wobble to Pluto. Which object, Pluto or its moon, is pulling with a greater amount of gravitational force?

a) Pluto is pulling Charon with greater force.
b) Charon is pulling Pluto with greater force.
c) They are pulling each other with equal force.
d) Neither exerts a gravitational force on the other.

Answer 1

The correct answer is c) They are pulling each other with equal force. This is based on Newton's Law of Universal Gravitation and his Third Law of Motion, indicating that Pluto and Charon exert equal gravitational forces on each other despite their difference in mass.

Step-by-step explanation:

The gravitational force between two bodies such as Pluto and its moon Charon is determined by Newton's Law of Universal Gravitation. According to this law, the force is proportional to the product of their masses and inversely proportional to the square of the distance between their centers. Even though Charon is about 1/2 the mass of Pluto, both bodies exert equal gravitational forces on each other. This is because gravitational force is mutual; the force exerted by Pluto on Charon is equal in magnitude but opposite in direction to the force that Charon exerts on Pluto.

This concept is a fundamental aspect of physics known as Newton's Third Law of Motion, which states that for every action, there is an equal and opposite reaction. In the context of the Pluto-Charon system, where Charon is in retrograde orbit and they are tidally locked to each other, it means that even though the masses are different, the gravitational force each exerts on the other is the same.