I can’t make the title fully understandable, so here is a longer explanation of what I want to know. 
When a Humanoid jumps, how exactly is the force calculated and applied? Is it calculated with a singular part’s mass multiplied by the JumpPower? Is it the JumpPower being applied to every limb of the character? Or is it another technique? 
All answers are appreciated, and I apologise if there’s already a topic identical to this. I just couldn’t find one covering this. 