Universal gravitation

Science

Definition

Newton's law stating that every object with mass attracts every other object with mass. The gravitational force is directly proportional to the product of the two masses and inversely proportional to the square of the distance between their centers.

Examples

  • The Earth pulling on the Moon to keep it in orbit while the Moon pulls on Earth causing tides
  • Calculating the gravitational attraction between the Sun and Earth to predict orbital motion
  • An apple falling from a tree — the same force that governs planetary orbits
Key Fact

F = Gm₁m₂/r², where G = 6.674 × 10⁻¹¹ N·m²/kg².

Related Terms

Orbital motion Newton's three laws Tides Earth-moon system

Study This Concept

Practice universal gravitation with free review games in these units:

Physics Unit 5: Circular Motion and Gravity