Reduced Gravity Pendulum
As you may have seen from the computer models, the period of a pendulum depends on the acceleration due to gravity. Normally, we cannot alter gravity in the typical non-magical physics classroom.
This past summer I had the pleasure of flying on a NASA Reduced Gravity Flight. To earn my ticket I had to design an experiment. I flew a pendulum on the flight. My team and I brought both a string and rigid rod pendulum.
We were able to observe the motion of the pendulum with both normal gravity, and simulated Lunar, Martian, and heavier gravities. The airplane simulates these levels of gravity by flying in wide parabolas, similar to a giant roller coaster ride.
There is a practical usage for using the relationship between a pendulum’s period and the acceleration due to gravity. Early in the 20th century, geologists used pendulums to detect areas on the Earth’s surface of increased (or decreased) gravity to detect mineral deposits and oil deposits.
I have provided the data from this flight. The pendulum bob itself was actually a Wireless Accelerometer made by Vernier Software. There is also video footage and one could likewise use image analysis. From looking at the video footage, one can see that often, the pendulum’s motion is NOT small angles. However, one can compare the period as measured from accelerometer data to the acceleration due to gravity with surprising results!
