Which statement best explains how Newton's law of universal gravitation shows that gravity is universal in nature?

• A. Gravity only acts between objects located on Earth, and it is negligible elsewhere in the universe.
• B. The gravitational force between two masses is proportional to the distance between them: $F\propto r$.
• C. Every pair of masses in the universe attracts each other with a force proportional to $m1$ and $m2$ and inversely proportional to the square of the distance between them: $F=G\frac{m1m2}{r^2}$.
• D. Gravitational attraction depends on an object's electric charge rather than its mass.

Answer: (C)

Verified step by step guidance

1. Recall Newton's law of universal gravitation, which states that every pair of masses attracts each other with a force.
2. Express the gravitational force mathematically as \(F = G \frac{m_1 m_2}{r^2}\), where \(F\) is the force, \(G\) is the gravitational constant, \(m_1\) and \(m_2\) are the masses, and \(r\) is the distance between their centers.
3. Understand that this formula applies universally to any two masses anywhere in the universe, not just objects on Earth.
4. Note that the force is proportional to the product of the two masses and inversely proportional to the square of the distance between them, showing the universal and predictable nature of gravity.
5. Conclude that this universality means gravity acts between all masses, regardless of location, which is why the correct explanation involves the formula \(F = G \frac{m_1 m_2}{r^2}\).