Notes on lesson on Force |


On completion of this lesson, students should be able to:

  • Explain Newton's Law of Gravitation
  • Differentiate between Gravity and Gravitation
  • Explain why acceleration due to gravity varies on Earth
  • Differentiate between mass and weight
  • Explain Free fall and Weight



The force of attraction between any two bodies in the universe is called gravitation. This note has information about universal law of gravitation, its effect and variables that affect gravitational force.

Gravitational Field

When a unit mass experience a force within a gravitational field then, the force is called gravitational field intensity. This note has brief explanation of gravitational field and its intensity.

Variation of Acceleration due to Gravity

Weight of the body is high at poles than in equator. This note has brief information about difference in gravity within our earth and illustrates how falling rate or acceleration due to gravity is independent of the masses of the falling bodies.

Free fall and Weightlessness

Weightlessness is the situation of having zero weight of a body with certain mass. This note has brief explanation of free fall and weightlessness.

Mass and Weight

The amount of matter contained in the body is called mass of the body. It is measured in kg. The weight of a body is defined as the force with which it is attracted towards the center of the planet. It is measured in Newton.