Swing in Time
Students examine the motion of pendulums and come to understand that the longer the pendulum string, the fewer the number of swings in a given time interval. Student groups conduct an experiment, collecting and graphing data on a worksheet. They see that changing the weight on the pendulum does not have an effect on the period.
Students examine the motion of pendulumsCopyright Wikimedia Commons http://upload.wikimedia.org/wikipedia/commons/2/21/Pendulum_animation.gif
Engineers use the motion concepts learned from pendulums in many applications, including timekeeping, earthquake detection, satellite orbits and energy dissipation. Control engineers incorporate pendulums into vibration isolation systems for manufacturing and industrial equipment, and controlling walking robots and rocket thrusters. Inverted pendulum systems monitor dam performance and structural behavior by detecting angular movement. Anti-sway software builds upon pendulum concepts to provide more safe and efficient operation of construction cranes, yard cranes, telescoping boom cranes and shipboard cranes.
After this activity, students should be able to:
- Describe the motion of pendulums.
- Collect data while experimenting with pendulums, and use that data to predict future behavior.
- Use collected data to explain the relationship between pendulum length and frequency.
- Give examples of situations in which engineers use pendulums.
- (activity extension) Use knowledge acquired from data analysis to create a pendulum that solves a design challenge.