These two questions struggled me for a long time: (. don’t know any of them

The question mentions height. That suggests grav pot energy, mghThe first pendulum comes down and gives the second one a kick.

The firsst pendulum is the same in each case, so it's velocity of approach is the same.

I'm thinking it's either conservation of enerrgy ke to pe, or momentum, or both

I'll keep pondering this maybe

I'm struggling to add an enclosure too

http://perendis.webs.com

1 is a answer of a question