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 speed the combined gliders will be

Question

Quizplus · Accepted Answer

Since the air track has zero friction, the momentum of the system is conserved. Before the collision, the momentum of glider A is 1 kg × 1 m/s = 1 kg m/s, while the momentum of glider B is zero. Therefore, the total momentum before the collision is 1 kg m/s. After the collision, the two gliders stick together and move as one object. Let v be their common speed after the collision, then the total momentum of the system is (1 kg + 5 kg) × v = 6 kg v. Since momentum is conserved, we have 1 kg m/s = 6 kg v, or v = 1/6 m/s. Therefore, the correct answer is (C) 1/6 m/s.

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