Consider the video you just watched. the two pucks of equal mass did not move linearly (they came to a stop) after the collision due to the conservation of linear momentum. however, since the two pucks mutual center of mass does not coincide with either of the pucks velocity vectors, they have angular momentum. this becomes evident after the collision when due to conservation of angular momentum the two pucks spin around their mutual center of mass.

the two pucks collide and stick together (they have velcro)due to angular momentum they spin.

part a

suppose we replace both hover pucks with pucks that are the same size as the originals but twice as massive. otherwise, we keep the experiment the same. compared to the pucks in the video, this pair of pucks will rotate

at the same rate.
one-fourth as fast.
four times as fast.
twice as fast.
one-half as fast.