Definition for Projectile motion
From Biology Forums Dictionary
1) A curved path that an object follows when thrown or propelled near the surface of the earth.
2) Projectile motion is the act of projecting an object into the air at an angle. A few real life examples of projectile motion are throwing a tennis ball, kicking a rugby ball or even long jumping.
To create this motion, something must first be thrown, pushed, launched outwards. After it has been done the ball gets to its highest point because the force it was thrown out first with has been lost. At that point it would be the highest point it can reach and its velocity will become zero. However, it does not just stop at midair, it will continue to move forward because the horizontal force still exists. It will continue to move forward until it hit the ground. The gravity will always bring the ball back down onto the floor.
