Into the Swing of Things
After watching a 1940 film clip of the "Galloping Gertie" bridge collapse and a teacher demo with a simple pendulum, student groups discuss and then research the idea of motion that repeats itself—specifically the concepts of periodic and harmonic motion. They become aware of where and how these types of motion occur and affect them in everyday applications, both natural (seasons, tides, waves) and engineered (swings, clocks, mechanical systems). They learn the basic properties of this type of motion (period, amplitude, frequency) and how the rearrangement of the simple pendulum equation can be used to solve for gravitational acceleration, pendulum length and gravity. At lesson end, students are ready to conduct the associated activity during which they conduct experiments that utilize swinging Android® devices as pendulums.