# Time Line Project

### By: Salwa Omar

## Johannes Kepler

Kepler proved the the orbital path of the planets were

*ellipses*(not perfect circles). He proved that when a planet is closer to the sun its orbital path is faster then ones farther away from the sun and slower. His research provided a complete*Kinematic*observation on motion of planets .## Isaac Newton

Isaac Newton realized that the falling motion of an apple and the motion of the moon were the same motion with the same force and gravitational force acting on it . He stated that the

*universal*force acting between two thing/objects was gravity. The*gravitational force*would equal the objects*weight*. Where g = 9.8 m/s2. The reason the moon orbits the Earth is it gravitational force. The Universal Gravitation is often called an*Inverse Square Law.*