This Demonstration is an animated 3D model of a projectile fired from above the Earth's equator, based on Newton's laws of motion and gravitation. According to this theory, after launch, a projectile is subject only to the Earth's gravitational attraction.
The differential equations determining the projectile's motion are .
In this Demonstration, air resistance and the effect of the Earth's rotation are not taken into account. The Earth is assumed to be a perfect sphere with diameter set to 1 and all lengths are scaled accordingly. The projectile is fired from a point directly above the equator where the escape speed is . The circular equatorial orbit is calculated using Kepler's formula, .
Snapshot 1: projectile returns to Earth
Snapshot 2: circular equatorial orbit
Snapshot 3: fired at a speed above escape velocity
Inspired by Enrique Zeleny's Demonstration "Projectile Launched around the Earth".
Graphic of the earth taken fromEd Pegg Jr's Demonstration "Geosynchronous Orbit"