Gravitation is the universal force of attraction between any two bodies having mass.
Gravity usually refers to the gravitational attraction exerted by the Earth or another celestial body.
Motion under gravity includes free fall, vertical projection, orbital motion and escape from a celestial body's gravitational field.
Gravity is one of the four fundamental forces of nature and is the weakest at the particle scale, but it dominates astronomical systems because it is always attractive and acts over unlimited distance.
Inside this chapter
What Motion under Gravity covers
01Motion Under Gravity
02Planetary Motion
03Kepler's Laws of Planetary Motion
04Newton's Universal Law of Gravitation
05Acceleration Due to Gravity
06Free Fall
07Mass, Weight and Apparent Weight
08Centre of Gravity and Stability
09Circular Motion of Satellites
10Escape Velocity
11Weightlessness and Microgravity
12Relative Motion and Earth's Orbital Speed
13Motion on a Smooth Inclined Plane
14Periodic, Oscillatory and Simple Harmonic Motion