Laboratory:
Vibrations and Mechanics of Machines Laboratory 
Using a simple pendulum, the value of g can be determined by measuring the length L and the period T. The value of T can be obtained with considerable precision by simply timing a large number of swings, but comparable precision in the length of the pendulum is not easily come by. For example, it's hard to estimate where exactly the center of the mass is. To overcome this difficulty we can turn a physical pendulum into a so-called reversible pendulum. Two knife-edge pivot points and two adjustable masses are positioned on the rod so that the period of swing is the same from either edge. The pendulum used in the instructional laboratories is diagramed below in the figure (1) and its adjustments are described in Setting it up.