Predict the period of a physical pendulum

• Choose a relatively simple shape. You must be able to compute the moment of inertia of the shape around its center.
• Cut out your shape from a sheet of stiff paper. Measure its mass M, and estimate the uncertainty in M. Place a mark at its center.
• Pick a pivot point which is located some distance from the center. Mark the pivot point, and measure its offset d from the center of mass. Estimate the uncertainty in d.
• Predict the period of this physical pendulum. Use the range of possible values of M and d to determine a range of possible periods (i.e., choose M and d to make period as large as possible, then to make period as small as possible). Write down your value in the form

  
  
                predicted period  P  =  _____  +/- ______ 
       

  and ask an instructor to write his or her initials next to your prediction.
• Stick a pin through the pivot point of your pendulum, and measure its period of oscillation. Use at least 10 oscillations, and at least 3 trials. Compute the average and standard deviation.

  
  
                measured period  P  =  _____  +/- ______ 
       

• Compare your prediction to the actual period.

Copyright © Michael Richmond. This work is licensed under a Creative Commons License.