Newton's Cradle, Simple Harmonic Motion

[godtripp]

Is it possible to see Newton's cradle in simple harmonic motion?

Im thinking that the period is the same as a simple pendulum, if not how would I calculate this?

 

[kuruman]

It is simple harmonic motion as long as you pretend that the five spheres are point masses. The velocity of the center of mass does not change through the multiple collisions, so you can view this as a single oscillating mass. Since the period of a simple pendulum is independent of the mass, then it is given by an equation that looks like ...