The motion of an object under the influence of gravity is determined by the acceleration of gravity, its launch speed, and launch angle provided air friction is negligible. This easy-to-follow tutorial helps the user comprehend how various components work together to determine trajectory: range, height, time, speed, and angle. This page is an interactive environment allowing the user to choose among related topics. The subjects are organized in flow charts that make it easy to move from one topic to a related item. This item is part of a larger collection under continuing development by Dr. Rod Nave, Georgia State University.