Question

A 1-kg mass is at rest and a 2-kg mass slide towards it at 1m / s on an air track. They collide and stick. The combined mass moves at

0m / s;
1/2 * m / s;
1.5m / s;
2/3 * m / s;
1/6 * m / s;




A 5000-kg freight car moving at 2m / s collides with a 10,000-kg freight car at rest. They couple upon collision and move away at 2m / s .
0.66m / s;
1m / s
None of these
1/3 * m / s

Answer 1

A 1-kg mass is at rest and a 2-kg mass slides towards it at 1m/s on an air track. They collide and stick. The combined mass moves at: 1.5m/s.

A 5000-kg freight car moving at 2m/s collides with a 10,000-kg freight car at rest. They couple upon collision and move away at 2m/s: None of these.

These are examples of elastic collisions in which the total momentum is conserved. The final velocity of the combined mass can be calculated using the conservation of momentum equation.

Step-by-step explanation: