Newton's cradle

Newton's cradle is a fancy toy that helps us learn about an important idea called conservation of momentum. Imagine that you have some marbles or balls that are all the same size and weight. Now, line them up in a straight line and then let the first marble go. This one marble will then hit the next marble causing it to move, and so on, until the last marble flies out.

Now, what do you think will happen if you did this again, but this time with two marbles at the beginning? When the first marble hits the next, like before, it will cause it to move, and then it will hit the third marble, causing it to move, and so on. But, this time, something really interesting happens. When the last marble flies out, the first marble doesn't just stop moving. Instead, it also flies out! And the same happens for any number of marbles, as long as they all weigh and have the same size.

This happens because of something called momentum. When the first ball hits the second ball, it transfers its momentum to it, causing it to move. But, since the second ball is also moving, it transfers momentum back to the first ball. This continues back and forth until it gets to the last ball, which then transfers momentum to the air outside, causing it to move outwards.

So, to summarize, Newton's cradle is just a fancy toy made of balls or marbles that are all the same weight and size. When you pull the first ball back and let it go, it hits the next ball, causing it to move, and so on until the last ball flies out. This happens because of something called momentum, which is when an object is moving and transfers that movement to another object. Pretty cool, huh?