Pendulums: To and Fro We Go
Today’s lesson focused on pendulums. The motion of pendulums was one of the many phenomena investigated by the famed scientist Galileo over 400 years ago and what he learned about them had a huge impact on the history of technology. The periodic motion of pendulums allowed for the invention of clocks and the standardization of time, and they still have many uses in modern society.
Students saw that a pendulum consists of a pivot point with a rope or wire attached to it and a mass on the end. The time it takes the pendulum to make one full oscillation back and forth is called the period. Here, gravity is the only force working on the pendulum. If we took the same pendulum and put it on the Moon, the pendulum would have a slower period due to less gravitational force. Some examples of items that use pendulums are metronomes and grandfather clocks.
For the activity, students constructed their own pendulums and then changed the length of the pendulum and measured how long the period was for the different lengths. They noticed a pattern: a longer length correlated to a longer period. They used this pattern to predict the length of the period for an even longer chain length. Predicting how a system will react if the variable is changed is an important scientific skill.
Students really enjoyed this activity!
To experiment with virtual pendulums at home, check out:
This video shows some of the cool patterns that a group of pendulum waves can make!
Para experimentar con péndulos virtuales en tu hogar, revisa este link:
El siguiente video muestra algunos de los efectos que un grupo de péndulos puede generar: