1. Universal Law of Gravitation
Every object in the universe attracts every other object with a force proportional to the
product of their masses and inversely proportional to the square of the distance between
them. F = G(m₁m₂)/d².
2. Free Fall
When objects fall towards the earth under gravity alone, they are in free fall. Acceleration
due to gravity (g) = 9.8 m/s².
3. Mass and Weight
- Mass: The measure of an object's inertia. It remains constant
everywhere.
- Weight: The force with which earth attracts an object (W = mg). It
varies with location.
4. Thrust, Pressure, and Buoyancy
- Pressure: Force per unit area (P = F/A).
- Archimedes' Principle: When a body is immersed in a fluid, it
experiences an upward force equal to the weight of the fluid displaced.
- Relative Density: Ratio of density of a substance to density of water.