Trying to update a variable multiple times

I’m trying to add resistance to this so it doesn’t infinitely spin, but I can’t update my velocity variable (b) multiple times

Is this connected to the other question you posted? 'cause it seems to me that you already solved the problem … right?

It’s not connected, I’m just trying to simulate gravity for fun

Ok, but I’m not sure I understand what you’re trying to achieve …
I don’t understand the role of c and the actions on the velocity b …

I renamed stuff to make it more clear

What should the animation do as you imagined it?

It would act as a pendulum with semi-realistic gravity

ok, sorry, I wasn’t able to understand how your formula works … so I wrote a new one:
Realistic pendulum:
https://www.desmos.com/calculator/ekzygvu6f4

ps: it can be further improved by updating T at each cycle