Can anyone point me to an in depth discussion of how things like mass and friction are conceptualized in phaser?

[fsboc]

for example, if I set restitution, friction, damping, gravity all to 0 then if I set the mass high enough objects will still slow down rapidly ... why is this? I'm just trying to understand how these things are related to each other in phaser and can't find anything after a bunch of googling. Thank you very much in advance! 

 

PS. I realize I can avoid dealing with this question by just setting mass to  a very small number, .001 seems to be just fine, but I would be cool to understand how phaser approaches this.