obtained by the law of momentum conservation: mCv=(mC+mB)v1,
the * * velocity of A, B and C, taking the system composed of the three as the research object and the velocity direction of C as the positive direction,
obtained by the law of momentum conservation:
② For A, I=mAv2- from the momentum theorem, and
I=6kg? m/s;
a: ① the maximum elastic potential energy of the spring is 12J;; ?
② the impulse of the spring to a is 6kg? m/s.