Physics Video Lectures of MIT
Here is the link to the excellent PHYSICS Video Lectures by Professor Walter Lewin of MIT. It's part of MIT Open Courseware...!! http://ocw.mit.edu/courses/physics/8-01-physics-i-classical-mechanics-fall-1999/video-lectures/ Professor Walter Lewin demonstrates that the period of a pendulum is independent of the mass hanging from the pendulum. This demonstration can be viewed on the video of Lecture 10. (Image courtesy of Markos Hankin, Physics Department Lecture Demonstration Group). Courtesy: MIT