Uploaded January 2026 | Updated September 2026, 3 weeks ago
Try This!...Swinging Pendulums
What do you think determines how quickly a pendulum swings? Some clocks in the Collection of Historical Scientific Instruments use pendulums to keep a consistent rhythm so clockmakers have known the science of swinging weights for hundreds of years.
Try some experiments to see how pendulums work.
What you’ll need:
Thin string or thread
Weights like nuts or washers
A way to suspend the pendulums like a dowel or stick
Scissors
Optional: protractor to measure angles
Steps:
Start by making some guesses about what will influence how quickly pendulums swing. The amount of time it takes a pendulum to swing back and forth once is called the period. How will the period change if the string is longer? What about having a heavier weight? Does pulling it back further make the period longer?
Set up some pendulums to test your guesses. This video shows a set up ready to test two situations.
*two pendulums of the same length but different weights (8 nuts vs 4 nuts)
*two pendulums with the same weight but different length strings
Test your pendulums! Do they swing together? Does one swing faster, getting out of sync, then aligning for a bit before going out of sync again?
What happens if you start the pendulum swing higher or lower? Does it still take the same amount of time to complete a period? What other variations can you create?
Don’t have the materials you need? This online simulation of pendulums will allow you to experiment with pendulum weight, length, and other variables.
Try This!...Swinging Pendulums
What do you think determines how quickly a pendulum swings? Some clocks in the Collection of Historical Scientific Instruments use pendulums to keep a consistent rhythm so clockmakers have known the science of swinging weights for hundreds of years.
Try some experiments to see how pendulums work.
What you’ll need:
Thin string or thread
Weights like nuts or washers
A way to suspend the pendulums like a dowel or stick
Scissors
Optional: protractor to measure angles
Steps:
Start by making some guesses about what will influence how quickly pendulums swing. The amount of time it takes a pendulum to swing back and forth once is called the period. How will the period change if the string is longer? What about having a heavier weight? Does pulling it back further make the period longer?
Set up some pendulums to test your guesses. This video shows a set up ready to test two situations.
*two pendulums of the same length but different weights (8 nuts vs 4 nuts)
*two pendulums with the same weight but different length strings
Test your pendulums! Do they swing together? Does one swing faster, getting out of sync, then aligning for a bit before going out of sync again?
What happens if you start the pendulum swing higher or lower? Does it still take the same amount of time to complete a period? What other variations can you create?
Don’t have the materials you need? This online simulation of pendulums will allow you to experiment with pendulum weight, length, and other variables.
