.....is a possible phenomenon occurrence , when two waves meet to form a greater resultant wave , at :
https://www.physics-and-radio-electronics.com/physics/waveinterference.html
Now , the problem is to play gravity ( free fall...) and rotational inertia ( free centrifugal pulsatory...) as "waves"(overlaping...) , let's say a spring mass system on a rotating (so,not swinging...) pendulum.
https://youtu.be/z6_NRNw88Jw
It's a syncro gravity-inertial "induction" of a mechanical oscillation?!
Al_ex