Jacobs Cavern was peculiarly rich in flint knives and projectile points.
In a vacuum, the projectile acted on by the force of projection begins to fall under the action of gravity immediately it leaves the bore, and under the combined action of these two forces the path of the projectile is a parabola.
In the motion of a projectile under gravity the hodograph is a vertical line described with constant velocity.
He was known as an expert in ancient Earth firearms and projectile weapons.
The parabola is the curve described by a projectile which moves in a non-resisting medium under the influence of gravity (see Mechanics).