Define projectile motion and projectile particle.

(N/A) Projectile motion is the form of motion experienced by an object or particle (a projectile) that is projected near the Earth's surface and moves along a curved path under the action of gravity only. The path followed by a projectile is called its trajectory.
$A$ projectile particle is any object that is given an initial velocity and then allowed to move in space under the influence of gravity alone. Examples include a ball thrown in the air,a bullet fired from a gun,or a javelin thrown by an athlete.