Two air track carts move along an air track towards each other.Cart A has a mass of 450 g and moves toward the right with a speed of 0.850 m/s.Cart B has a mass of 300 g and moves toward the left with a speed of 1.12 m/s.What is the total momentum of the two-cart system?
A)0.047 kg ∙ m/s toward the right
B)0.719 kg ∙ m/s toward the right
C)0.719 kg ∙ m/s toward the left
D)0.750 kg ∙ m/s toward the right
E)0.750 kg ∙ m/s toward the left

Question

Quizplus · Accepted Answer

The total momentum of the system can be calculated by adding the momentum of each cart, taking direction into account. Cart A's momentum is $0.450 \, \text{kg} \times 0.850 \, \text{m/s} = 0.3825 \, \text{kg} \cdot \text{m/s}$ toward the right, and Cart B's momentum is $0.300 \, \text{kg} \times 1.12 \, \text{m/s} = 0.336 \, \text{kg} \cdot \text{m/s}$ toward the left. Converting the direction of Cart B's momentum to the right for subtraction gives $0.3825 - 0.336 = 0.0465 \, \text{kg} \cdot \text{m/s}$ toward the right, which rounds to $0.047 \, \text{kg} \cdot \text{m/s}$ toward the right.

Two Air Track Carts Move Along an Air Track Towards