Gravitation — Important Questions

Directly proportional to the product of their masses, Inversely proportional to the square of distance between them, Acting along the line joining their centers

The universal law of gravitation states that gravitational force is directly proportional to the product of masses, inversely proportional to the square of distance, and acts along the line joining the centers of the two objects.

Mass remains constant everywhere, Weight varies from place to place, Weight is the force with which Earth attracts an object

Mass is constant everywhere and is a scalar quantity. Weight varies with location because it depends on gravity (W = mg), and weight is a force measured in newtons, not kilograms.

1/6

The weight of an object on the moon is 1/6th of its weight on Earth because the moon's gravitational acceleration is about 1/6th of Earth's due to its smaller mass and radius.

Force acting perpendicular to a surface

Thrust is the force acting perpendicular to a surface. When you press a drawing pin, the force you apply perpendicular to the pin's head is thrust.