Simple Harmonic Motion

In 1581, the 20-year-old Galileo Galilei was a medical student in Pisa, Italy. His life changed when he wandered into the cathedral and noticed a chandelier swinging on a long chain. Galileo discovered that no matter how wide the swing was, the chandelier took the same amount of time to complete its swing. Galileo confirmed this observation with experiments and publicized his results, leading to a career as a legendary pioneer in physics and astronomy. In the meantime, he began the science of harmonic motion and inspired the invention of the pendulum clock.

The Simple Harmonic Motion Gizmo explores the oscillations of pendulums and springs. Students manipulate the mass and stiffness of the spring and the mass and length of the pendulum, as well as the strength of gravity, to see how each factor affects—or doesn’t affect—the period of the motion. All periods are measured with a stopwatch, illustrating the importance of accurate measurement skills and gathering data from repeated trials. Based on their data, students can derive formulas for the period of a pendulum and the period of an oscillating spring.