Colliding Marble Question?

Question

If you have five marbles lined up and roll a marble into them - one marble shoots off the end

If you roll two marbles into the the row of 5 then two marbles shoot off the end

Both of these scenarios make perfect sense.... now here's the twist.....

Set up one marble just in front of the 5 - roll two marbles into the single marble so that it strikes the five.....

How many marbles shoot off the end? And why?

Answer 1

2 marbles. It will be the one that was sitting alone, as well as the last of the 5. In these perfectly elastic collisions, which we idealize for this thought experiment, the momentum is transferred without loss down the line, ending up only in the last recipient. Similarly, if you shot 2 marbles at a single marble sitting alone, only the second of the 2 marbles would stop. The first would keep moving, now with the one that had been sitting alone, so the quantity of moving marbles would be 2, the same as what was moving in the beginning, even though it is different individual marbles.

Answer 2

An equal and opposite reaction...It's basically the whole idea of physics. When one object strikes another it will repel with an equal and opposite reaction (Newton's third law)

Answer 3

off the end of the 5 marbles? 1 marble b/c only marble hit the group, duh