I have been racking my brains for 2 days. I am working on a homebrew video game and am having problems with the physics. say i have 3 objects, one moving left to right(1) the other 2 moving right to left(2,3). they all have the same mass and velocity. Say the mass is 100 units and the velocity is 1 unit. So far i have been able to get the code to work where if object1 collides with object2 then they both stop moving. What I want to happen is if object3 collides with the back of object2 that it will transfer it's force to both objects and I will get movement in all 3 in the right to left direction. Friction is zero, not a factor in this. I think what I am mostly stuck on now is how to calculate the velocity of the group of objects when that 3rd one starts pushing. Thanks EDIT forgot to mention, right now i am only dealing in a 2d plane with the forces only being applied in the X axis.