The velocity of the projectile in the horizontal direction is always constant
The answer is: gravity.
Researchers always talk about the movement of projectiles and how they are launched, but the important point is that the velocity of the projectile in the horizontal direction is always constant.
Anyone can easily record this when you release the ball, for example, the ball will move at a constant speed in the horizontal direction and this means that the ball will always stay on its initial trajectory.
And it doesn't matter how much the ball moves in the vertical direction because it won't affect the speed in the horizontal direction, it's always the same.
This means that anyone can fully understand how this information can be used in everyday life, be it in sports, civil engineering, or any other field that requires shooting projectiles.
