projectiles
Objects that are launched into the air are called projectiles . The path followed by a projectile in motion is called a trajectory . The image of the snowboarder in the chapter introduction showed his trajectory; every object has a trajectory even when we cannot see it. Projectile motion , or the object's trajectory, is described in terms of position, velocity, and acceleration. Even with only an object's current location, velocity, and acceleration, we can calculate when and where the object will land. Our knowledge that perpendicular components of vectors do not affect each other allow us to easily analyze the motion of projectiles.