*, brainliest to first correct answer*

a roller derby exhibition recently came to town. they packed the gym for two
consecutive weekend nights at south's field house. on saturday evening, the
68-kg anna mosity was moving at 17 m/s when she collided with 76-kg sandra
day o'klobber who was moving forward at 12 m/s and directly in anna's path.
anna jumped onto sandra's back and the two continued moving together at
the same speed. determine their speed immediately after the collision.

show your work, so i can follow through