I can’t think of anything extra to add to this video it is fairly self-explanatory. It might be interesting to work out how much energy is lost with the collision between the lead balls. 1mv in and 1mv out as momentum is conserved but 1/2mv2 in and ½(5m)((1/5)v)2 out which is 1/5 of the original energy out. Where did it go? If there were two lead balls the energy out would be half of the energy in. Three balls it would be one third, four balls, one quarter. An infinite number of balls and the energy out is so close to zero that it does not matter. Where did the energy go?