A 3.0-kg object moves to the right at 4.0 m/s. It collides head-on with a 6.0-kg object moving to the left at 2.0 m/s. Which statement is correct?
A) The total momentum both before and after the collision is 24 kg ∙ m/s.
B) The total momentum before the collision is 24 kg ∙ m/s, and after the collision is 0 kg ∙ m/s.
C) The total momentum before the collision is 0 kg ∙ m/s, and after the collision is 24 kg ∙ m/s.
D) The total momentum both before and after the collision is zero.
E) None of the above is true.

Question

Quizplus · Accepted Answer

The total momentum before the collision is zero because the momentum of the 3.0-kg object (3.0 kg * 4.0 m/s = 12 kg∙m/s) is canceled out by the momentum of the 6.0-kg object (6.0 kg * -2.0 m/s = -12 kg∙m/s). Since momentum is conserved, the total momentum after the collision is also zero.

A 30-Kg Object Moves to the Right at 4