Space
Three-Frame Center-of-Mass Datum
Stand and locate your center of mass, first taking the floor as the reference frame, then the pelvis, then the head. Identify which frame makes the smallest motion most legible, and which frame conceals it.
Full Lesson Notes
Complete Practice
Stand and locate your center of mass, first taking the floor as the reference frame, then the pelvis, then the head. The center is one physical thing; its coordinates differ in each frame. Shift weight slowly side to side and report the center's motion three times — once per frame. Identify which frame makes the smallest motion most legible, and which frame conceals it.
