In this lab our AP Physics 1 students explored simple harmonic motion. By hanging a mass on a spring, each lab group was able to produce predictable up and down motion—in other words, simple harmonic motion. The students then positioned a motion detector under each spring-mass system and recorded the position and velocity of the mass with a computer program. Students then analyzed the motion to find the motion’s amplitude, period, and frequency, and well as the relationship between velocity and position. In the end, each lab group formulated an equation that predicted the motion of their spring-mass system and tested it by graphing their equation alongside the original data. As a result, the students recognized that simple harmonic motion is actually sinusoidal motion, and that if they can measure the properties of a spring-mass system then they can predict what will happen before ever observing the motion.