History of parabolic motionHistory of parabolic motion

This illustration reflects the general opinion before Galileo which followed largely Aristotelian lines but incorporating as well a later theory of "impetus" - which maintained that an object shot from a cannon, for example, followed a straight line until it "lost its impetus," at which point it fell abruptly to the ground.

Later it was realized that projectiles actually follow some sort of a curved path, but what sort of curve? No one knew until Galileo.

History of parabolic motionHistory of parabolic motion

Galileo reasoned that a projectile shot from a cannon is influenced by two - the motion that acts vertically and horizontally at the same time.

Here is a page from one of Galileo's manuscripts in which he writes down the figures he obtained in performing this experiment himself.

History of parabolic motionHistory of parabolic motion

The curve has an exact mathematical shape - it is one the Greeks had already studied and called the parabola.

By firing the launcher at 45 degree angle we will acquire the longest flight.

The longest flight distance

1. Attach the projectile launcher to a wide and stable surface and then place three cups filled with sand

2. Load the projectile launcher with a sphere

3. Set up the launcher so the projectile would be launched and sphere landed in on of the cups

4. With the attached protractor, measure the degree that the sphere will be shooting from the launcher

5. Set up the protractor at a 40 degree angle and then shoot the sphere from this point

6. Repeat the fifth step, however each time, change the angle. The next two angles that will be tested out in this procedure are 45 degrees are 55 degrees.

By firing the launcher in 45 degree angle, we acquired the longest flight of the sphere.