These are the Kepler's laws of planetary motion.
This law relates a planet's orbital period and its average distance to the Sun. - Third law of Kepler.
The orbits of planets are ellipses with the Sun at one focus. - First law of Kepler.
The speed of a planet varies, such that a planet sweeps out an equal area in equal time frames. - Second law of Kepler.
Explanation:
The center of gravity is near the grip and does not change during throw. "Throwing through the tip," a popular term of how to throw a javelin, means throwing through the grip or center of gravity. The center of pressure is the aerodynamic force of drag and lift on the javelin.