Consider Gliders That Slide Friction-Free Along a Horizontal Air Track

Multiple Choice

Consider gliders that slide friction-free along a horizontal air track.Glider A has a mass of 1 kg,a speed of 1 m/s,and collides with glider B,which has a mass of 5 kg and is at rest.If they stick upon collision the combined-glider speed will be

A) 1/4 m/s.
B) 1/5 m/s.
C) 1/6 m/s.
D) 1 m/s.
E) none of the above