In this lesson, students continue to explore the forces acting on swing set equipment and the motion that results. Science activities focus on balanced and unbalanced forces as demonstrated by pendulums. Lessons learned from measuring pendulum motion are applied to observations of swings. These observations will, in turn, be used to design the swing component of the swing set. Mathematics activities include measuring pendulum motion as well as ranking design alternatives. English language arts (ELA) activities focus on preparing and evaluating arguments for proposed designs. A materials list, teacher background information, safety practices, Internet resources, and outcomes are provided. This book selection includes the Table of Contents, About the Editors and Authors, Acknowledgments, and Index.