In Newton's law of universal gravitation, which two quantities determine the magnitude of the gravitational force between two point masses separated by a distance $r$?

• A. The masses of the objects and their velocities relative to each other
• B. The electric charges of the objects and the separation distance $r$
• C. The two masses ($m$ and $M$) and the separation distance $r$
• D. The masses of the objects and the temperature of the surrounding medium

Answer: (C)

Verified step by step guidance

1. Recall Newton's law of universal gravitation, which states that the gravitational force between two point masses is proportional to the product of their masses and inversely proportional to the square of the distance between them.
2. Identify the two key quantities involved: the masses of the two objects, usually denoted as \(m\) and \(M\), and the distance between them, denoted as \(r\).
3. Write down the formula for the gravitational force: \[F = G \frac{m M}{r^2}\] where \(G\) is the gravitational constant.
4. Understand that the gravitational force depends only on these two quantities (the masses and the distance), and not on other factors like velocity, electric charge, or temperature.
5. Conclude that the magnitude of the gravitational force is determined by the two masses and the separation distance \(r\).