In Physics lab we performed a simple pendulum with an apparatus that involved a cylindrical mass. We measured the period dependence on mass, amplitude, and length.
Throughout our experimentation we assumed that the mass used behaved similar to a point mass.
After analyzing our data we noticed some deviation from theory.
I am attempting to demonstrate that this deviation is due to the assumption that the mass is a point mass., and would like to determine the magnitude of the error I can attribute to this.
For a pendulum with a point mass the net torque tau is
tau = I*alpha = F*d where I is the moment of inertia of the weight/mass
and F is the component of the gravitational force acting perpendicular to the arm length of the pendulum
The Attempt at a Solution
I am trying to show that in addition to the torquing force causing the mass to continue moving in its circular motion path, at the high point of the trajectory an additional torquing force is causing the cylindrical mass to fall (since the center of mass of the weight is no longer underneath the base there's a torquing force causing it to change its orientation).
However, I don't know how to determine what this torquing quantity is?
Can someone guide me in the right direction?