# What is projectile motion? (with photo)

A soccer ball being kicked is an example of projectile motion.

Projectile motion is a physical phenomenon that occurs when an object is projected by a force that ceases to exert influence on the object after it is launched. The laws of physics cause objects to follow a very particular path when they are thrown this way. A classic example is the soccer ball, which turns into a projectile when kicked by a player.

Most people are familiar with Isaac Newton’s statement that an object in motion tends to stay in motion. This is known as inertia. Inertia plays an important role in projectile motion because it explains why an object keeps moving without any source of propulsion. There is also a force at play: gravity. Gravity explains why the soccer ball in the example above bounces back to Earth instead of moving continuously through the air.

The trajectory of a projectile is approximately parabolic. When it is released, inertia helps it move upwards against gravity, but eventually the pull of gravity becomes too strong and the object starts to fall back towards Earth. The object is also traveling horizontally, so the object’s path creates an arc. Eventually, the object will hit the Earth and stop, and in the case of the soccer ball, it will be kicked by another player.

It is important to understand how projectile motion works. Historically, many armies struggled with the concept because they didn’t understand how arrows, cannonballs, bullets, and other projectiles moved through the air, which made aiming correctly difficult. The physics behind this type of motion also plays a role in sports and many other activities, which is why questions involving this concept ask people to use mathematical formulas to determine which path a projectile will take in so many physics tests.