Question

The linear momentum of a system of many identical billiard balls in motion on a table is determined by:

-the difference between the fastest and the slowest ball.

-the total mass of all balls combined.

-the speed of the fastest ball.

-the velocity of every individual ball.

-the radius of the billiard balls.

Answer 1

Here we use conservation of linear momentum. The momentum of the first ball is transferred to the momentum of other balls on the table. The momentum of balls after the collision must be equal to the momentum of the initial ball. So whenever objects collide in the absence of external forces, the net momentum of the objects before the collision equals to the net momentum of the objects after the collision.

There are some requirements for the conservation of linear momentum like:

1. The mass of the system must remain constant during the interaction.

2. The external force on the system must be zero.

So here the right option should be the combined mass of the balls.