Question

a billiard ball moves with $3\\ \mathrm{kg} \cdot \mathrm{m}/\mathrm{s}$ of momentum and strikes three other billiard balls. what is the total momentum of the balls after the collision? (1 point)

\bigcirc it depends on the mass of each ball.

\bigcirc less than $3\\ \mathrm{kg} \cdot \mathrm{m}/\mathrm{s}$

\bigcirc $3\\ \mathrm{kg} \cdot \mathrm{m}/\mathrm{s}$

\bigcirc more than $3\\ \mathrm{kg} \cdot \mathrm{m}/\mathrm{s}$

Explanation:

Step1: Recall Momentum Conservation

In a closed system (no external forces), the total momentum before a collision equals the total momentum after the collision. Here, the billiard balls form a system with no external forces (assuming ideal conditions like no friction, etc.).

Step2: Apply to the Problem

The initial momentum of the system (one ball) is \( 3\ \text{kg}\cdot\text{m/s} \). After the collision (with three other balls), the total momentum of all balls (system) must remain equal to the initial momentum due to the law of conservation of momentum.

Answer:

\( 3\ \text{kg}\cdot\text{m/s} \) (corresponding to the option: \( 3\ \text{kg}\cdot\text{m/s} \))