A Pair of Identical Balls Are Connected by a Massless

Multiple Choice

A pair of identical balls are connected by a massless rod and thrown straight up into the air, such that the center of mass of the pair reaches a maximum height of 13.2 m above the point of release. On the way up, when the center of mass is at 6.6 m above to point of release, the velocity of one ball is measured to be 7.7 m/s straight downward. What is the velocity of the other ball at this time? Ignore air resistance.

A) 30.2 m/s up
B) 23.8 m/s up
C) 19.1 m/s up
D) 15.7 m/s up
E) 3.7 m/s up