Projectiles are objects that are under the sole influence of gravity. They represent a form of two dimensional or projectile motion. Neglecting air resistance, a projectile has a constant horizontal velocity and constant downward free-fall acceleration. In the absence of air resistance, projectiles follow a parabolic path or trajectory.

In order to produce motion that is not strictly linear, an object (projectile) must have 2 independent motions that act at right angles to each other.

 

With curved motion, now all kinds of motion are possible.

 

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