How to handle multiple simultaneous elastic collisions?

Question

I\'m computing the result by colliding pairs of 2D convex objects (without rotation), using the basic equations on wikipedia. However, when there are dependencies, like two obj

Answer 1

Do the individual collisions one-by-one, but always use the initial velocity of each object. When done, add up the velocity-changes for each object.

(v1_1,v3_1) = collide(u1,u3,m1,m3)
(v2_2,v3_2) = collide(u2,u3,m2,m3)
v1 = u1 + (v1_1 - u1) = v1_1
v2 = u2 + (v2_2 - u2) = u2_2
v3 = u3 + (v3_1 - u3) + (v3_2 - u3) = v3_1 + v3_2 - u3

This way, it will not be order-sensitive.