This video lesson will present Gravity Assist, or what is wrongly referred to as the gravitational slingshot. “Gravity assist” is a maneuver performed by interplanetary spacecraft to travel farther on less fuel. It is a classic exercise in Newtonian mechanics. The basics of this lesson are covered in high school physics curricula: conservation of linear momentum (to explain rocket propulsion), angular momentum, Newton's law of universal gravitation, and energy conservation. These concepts will be combined to explain orbits in the solar system. Gravity assist turns out to be carefully choreographed jumps between orbits. Only one topic reviewed in this lesson is not usually covered in high school curricula: that is distances in the solar system. A quick introduction to distances in the solar system will be enough to put the problem of fuel constraints in interplanetary travel into perspective and also to later highlight the importance of gravity assists in solving this fundamental problem. In short, “Gravity Assist” will integrate many seemingly disparate parts of high school Newtonian mechanics to present and explain a real application. Classroom activities will be group problem-solving, masses attached to strings and rotated over head, marble collisions, baseball/tennis/table tennis/badminton. Detailed directions for each of the classroom video breaks can be found in the Teachers Guide document, which can be found on this page under the menu item "For Teachers".