Why is Newton’s cradle (Newton’s balls) described as an “almost-ideal” closed system?

Answer 1

Why is Newton’s cradle (Newton’s balls) described as an “almost-ideal” closed system?

Can someone please help me 😭

Answer 2

Because gravity and friction is gonna be a effect on the balls

Answer 3

it is a closed system because there is hardly any forces acting on it. only gravity and some air resistance. It is a perfect example of conservation of energy and momentum: See here:
w w w dot scienceabc.com/pure-sciences/what-is-newtons-cradle-and-how-does-it-work.htmlmomentum.

Answer 4

Thanks Korra!

Answer 5

Well first u have to add 9 plus 4