| Universal Law of Gravitation |
Force of gravitational attraction between the Earth and other objects is inversely proportional to the distance separating the earth’s center from the object’s center. |
| Centripetal Acceleration |
Any object moving in a circle will have an acceleration vector pointed towards the center of the circle. |
| Inverse Square Law |
Power intensity per unit area from point source. If sun rays strike the surface of a planet at a right angle, varies inversely according to the square of the distance from the source. |
| Free Fall |
Gravity is the only force acting on an object. |