* Gravity: The most significant factor is gravity. The moment the cannonball leaves the barrel, it starts falling towards the Earth. This downward pull creates a curved trajectory.

* Air Resistance: Air resistance also plays a role. The ball experiences friction as it moves through the air, slowing it down and affecting its path.

* Initial Velocity: The angle at which the cannonball is fired also affects its trajectory. A cannonball fired straight up will have a very different path than one fired at a 45-degree angle.

In summary: A cannonball follows a parabolic trajectory, which is a curved path influenced by gravity and air resistance.