14-May-2015 Inertia of a Triangle

Purpose

The purpose of this experiment is to find the moment of inertia of the triangle with the air table.

Experiment

Before we use the air table to find the moment of inertia for the triangle we first derive a theoretical moment of inertia for the triangle. This is done by first finding the inertia for the triangle about the edge of the triangle, then using the parallel axis theorem to find out what the inertia about the center of mass is.  

Now that we have found the inertia of the triangle we set up the air table with the triangle on it, and connect the air table to a computer with logger pro. We then attache a hanging mass to end of a string and on the other end to the torque pulley which will cause the triangle on the air table to spin. one we let go of the hanging mass we start collecting the data on the position and angular velocity of the triangle. 

Once we have collected the data we analyze the graph and find the slope of the angular velocity of which would give us the angular acceleration. We take the slope of the velocity as the hanging mass rises and as it falls then take the average of the the two.

Once we have found the average acceleration we used a combination of tangential force and Torque to find the inertia of the triangle. 

After we did the percent error calculations we can see that we are very close, the cause for error can be cause by friction between the disks. the air pressure not being enough or being too much, and that the disk is not completely perpendicular to the disk.