A projectile is an object upon which the only force acting is gravity. Many projectiles not only undergo a vertical motion, but also undergo a horizontal motion. That is, as they move upward or downward they are also moving horizontally. There are the two components of the projectile’s motion – horizontal and vertical motion. And since perpendicular components of motion are independent of each other, these two components of motion can be discussed separately. The goal of this part of the lesson is to discuss the horizontal and vertical components of a projectile’s motion; specific attention will be given to the presence/absence of forces, accelerations, and velocity.

A basketball being thrown up to hoop fits. When shooting, ball follows the same direction as a projectile in motion. Doing free throw is a projectile. It is related to a projectile as the force exerted upon the basketball is a push. The basketball is then projected horizontally and vertically, causing, if the proper shooting technique is applied, the basketball to rotate, elevate, and finally swish through the net. The horizontal and vertical components are both independent, and there for do not effect each other. The arch caused by the basketball is a result of the gravitational pull upon the basketball, and if a basketball was thrown without gravitational pull acting upon it, the basketball would travel continuously without arching. Therefore, playing basketball in space would be an absurdity.

Any projectile thrown, such as a ball, can be considered to have a vertical and horizontal velocity component, as shown in this diagram (blue=horizontal velocity component, red=vertical velocity component).

Throughout the path of the projectile, change occurs only in the vertical direction due to the influence of gravity, while the horizontal component of the velocity will not change. The vertical velocity of the projectile gets smaller on the upward path until it reaches the top of the parabola. At the top of the parabola, the vertical component of the velocity is zero. After that point, the vertical component changes direction and the magnitude increases in the downward direction and the vertical distance travelled during each subsequent time interval increases.

In basketball, application of projectile can be seen for there is time of flight (the time taken to hit the ground), with vertical displacement, initial velocity, acceleration due to gravity, distance travelled, and angles in degrees.