In this video series, a pendulum bob is released from rest and allowed to swing back and forth. Each of the videos shows a different situation. Three quantities are varied in the video:

String Length: either 67 cm or 45 cm
Mass: either 1.0 kg or 0.5 kg
Initial Displacement***: either 10 cm or 20 cm

***Initial displacements are approximate. By carefully examining the video it is possible to determine a more precise value.

All videos were shot at 50 frames per second.

The apps for these videos have a simplified interface without automated plotting or graphical analysis tools.

Questions:

1. Does string length affect the period of the pendulum?
2. Does hanging mass affect the period of the pendulum?
3. Does initial displacement affect the period of the pendulum?