JAMB Physics 2012 Paper

Concept:Newton’s law of universal gravitation: $F = \frac{G M m}{r^2}$, so $F$ depends on the distance $r$ between the centres of the two masses.Explanation:From $F = \frac{G M m}{r^2}$, the gravitational force is inversely proportional to the square of the distance: $F \propto \frac{1}{r^2}$.As the rocket moves away from the Earth, $r$ increases, so $F$ decreases.Equivalently, $F$ increases as $r$ reduces.$G$ is a universal constant, and $F$ does not remain constant.Answer:A. increase as r reduces