Animated demonstration of projectile trajectory

Two revolutionary discoveries involving conics have been made at the beginning of the 17th century. Johannes Kepler (1571-1630) published his three laws of planetary motion in 1609 and 1619. In a major revision of Copernicus' heliocentric theory, Kepler placed the planets on elliptical orbits with the sun at their common focus. In a momentous departure from the Aristotelian theory, Galileo Galilei (1564-1642) has realized that the motion of material objects could be split into independent components, say horizontal and vertical for a projectile. This understanding led him to revising even his own beliefs. As he himself wrote, "... where the senses fail us reason must step in." By 1604 he concluded that projectiles travel along parabolic trajectories. However, the results had not been published until 35 years later.

The applet below has been inspired by a jumping water sculpture at the DisneyWorld.

This applet requires Sun's Java VM 2 which your browser may perceive as a popup. Which it is not. If you want to see the applet work, visit Sun's website at, download and install Java VM and enjoy the applet.

What if applet does not run?

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