The purpose of this lab is to find the period of a physical pendulums, we did this with a metal ring and a half circle at two different points.
Experiment
The set up for the first part of the experiment is to find the theoretical period of the ring though using our knowledge of torque, inertia, and periodic motion.
Once we found out the theoretical we then actually set up a stand with a nap sticking out and hanging the ring and see what the actual period of the ring is. We found the period of the ring by hooking it up to the lab pro and using a photogate.
We then calculated the percent error of the period and see that we are the error was indeed very small. the cause for the error could be that is was not swinging perfectly side to side and may have had some diagonal movement.
We then do the same for a semi circle, however the difference is that we have to find the center of mass of the semi circle first. After that we then find the moment of inertia of the semi circle about it edges, then use the parallel axis theorem to find the inertia of the semi circle about the center of mass with the shift being the center of mass of the semi circle. Once we have found the inertia about center of mass of the semi circle we then use the parallel axis theorem again to find the inertia about the outer edge of the semi circle. Once we have found the inertia at both points we the find the theoretical period like we did previously with the relationship between torque, inertia, and periodic motion.
After our calculations we started the experiment by attaching the half circle to the top the and then the bottom and swinging it to see what the period would be.
After we found out what the actual period was we then caculated the percent error between the theoretical and actual. What we found was the error was actually very small and that what caused the error was again that it may have not swung perfectly side to side and had some diagonal movement
