Question

1. If a model train car with a momentum of 12 kg•m/s collides with a 2 kg model train car that is not moving, what is the total momentum of both cars after the collision?

Answer 1

Answer:

$P_{f} = 12 \ kg.m/s$

Explanation:

Given data:

Momentum of moving model train, $P_{1} = 12 \ kg.m/s$

Mass of the stationary model train, $m = 2 \ kg$

Initial speed of the stationary model train, $v = 0$

Assume there is no external force is acting on the given train system.

In this case, the total linear momentum of the trains would be conserved.

Let the final linear momentum of the trains be $P_{f}.$

Thus,

$P_{i} = P_{f}$

$P_{1} + P_{2} = P_{f}$

$P_{1} + mv = P_{f}$

$12 + 2 \times 0 = P_{f}$

$\Rightarrow \ P_{f} = 12 \ kg.m/s.$