Projectile motion, a cornerstone topic of introductory physics, is usually a student’s first exposure to the problem-solving techniques used in this subject. Often, this is an inactive learning experience—students work with pencil and paper to read and solve projectile motion problems (e.g., diagrams and descriptions of balls being hit, kicked, and launched). In the activity described in this Idea Bank, however, students create their own problems by applying their abstract knowledge of projectile motion to something familiar: a Wiffle ball. This activity—which can be done in one 45-minute class period—aligns with National Science Education Standards for force and motion (NRC 1996).