in a harmonic pendulum, the lengths are increasing monotonically; the lengths are measured so that in a defined set of oscillations (i.e. 20 cycles in 20 seconds), each next string will decrease by 1 cycle per second. In this way, they come back into phase each 20 seconds.
a) If you designed your own harmonic pendulum with 10 individual strings, what are a set of lengths that would work?
b) When are they all exactly out of phase? (each pendulum was exactly opposite in its position)
c) What are some other times in this cycle that you see a pattern when sets of pendulums seem to match up?