Basically I'm trying to measure the moment of inertia of a hollow rod using bifilar pendulum. I will rotate the rod, and measure the period, and use the written formula to calculate the moment of inertia.
The problem is that I cannot seem to remove the lateral movement of this rod when I push it to the side on one end.
This is how my rod looks like. It is a hollow cylinder that will rotate about its y-axis. However, when I give it a push to the sideway to rotate, (that is, rotate around the y-axis) it will move back and forth in x-axis direction and I'm worried if this will affect my experimental result.
Is there any good and creative way to reduce/remove this annoying back and forth motion of the rod without inputting another possible variable to consider in the experiment?
Thanks for any help in advance.
(P.S. I'm new to this forum, so please understand if I did not follow any formats or whatever :) )