Thanks for ur answers. Pls explain to me then how that moving balls which knock each other forever works?

Question

You know, the one that knocks the other etc. and then which send the force back to knock the first one again and then which continues on forever etc.

Answer 1

There are two king of gadgets that do that: the pure mechanical one and the electrically assited one.
The purely mechanical one does not go on forever: it works for a long time because the balls are very hard and during the collisions, they tranfer to the next ball a maximum amount of energy (there are very little loss during the elastic collision).
The electrically assisted one has a small electro-magnet underneath! That magnet is activated synchroneously with the movement of the balls, and gives a tiny impulse to the balls during the movement, making it lasting forever. (The magnet gives the same amount of energy that what is lost during the collision).
There are many gadgets with metalic balls doing the same thing, not only a chain of balls...

Answer 2

It doesn't work forever (unless it's electric and plugged in). It might take a while, but it will eventually stop because each impact loses energy in the form of sound, friction, heat etc.

There's no such thing as a perpetual motion machine.

Answer 3

They don't go on forever. Just for a long time. And for that time, they just transfer energy until friction slows them down.

Answer 4

the moving balls are also called momentum balls, since momentum is conserved, the ball seems to move forever, but it ll lose energy over time mainly due to air resistance anf sound energy and comes to a gradual stop

Answer 5

it won't go forever, because each time, some of the energy dissipates, it can go for a long time, but not forever

Answer 6

It works well with smooth metal balls.The force is transferred recipricaly.It wont go on forever.The setup makes it efficiently transfer force or not.