Gravitation
High School
Definition
The attractive force that acts between any two objects with mass. Newton's law of universal gravitation states that this force increases with the masses and decreases with the square of the distance between them, governing the motion of planets and satellites.
Worked examples
\(F = G \frac{m_1 m_2}{r^2}\)
Newton's law: gravitational force depends on both masses and inversely on distance squared.
Earth (\(6 \times 10^{24}\) kg) pulls you down; you pull Earth up with equal force.
Gravitation is mutual—both objects attract each other, no matter how different their masses.
Double the distance between two masses, and the gravitational force drops to one-quarter.
The inverse-square relationship means small changes in separation cause large changes in force.
Common mistakes
- Gravitation only acts on objects near Earth's surface. → Gravitation acts between any two masses anywhere in the universe. Every mass attracts every other mass, including stars, planets, and everyday objects.
- Heavier objects fall faster because gravity pulls them harder. → All objects fall at the same rate in a vacuum (ignoring air resistance). Greater mass means greater force, but also greater inertia—the two effects cancel in free fall.
- Gravity disappears in space or on the Moon. → Gravity is weaker farther from massive bodies, but never zero. Astronauts feel weightless because they are in continuous free fall, not because gravity is absent.
Where you'll use it next
You'll apply gravitation when studying orbital mechanics, satellite motion, tides, and planetary systems in physics and astronomy, and later in understanding general relativity and cosmology.
Found in 1 StudyPug lesson
11th Grade11th
See also
Planetary MotionGravitational ForcesNewton's first lawNewton's second lawCelestial BodiesOrbital Patterns
Reviewed by Pat Cheng, M.Ed. — StudyPug Curriculum Lead · Last updated June 6, 2026