Description Newton's Cradle
Newton's Cradle is physics you can touch. It impressively demonstrates the laws of momentum and energy conservation in a mechanical system.
In a Newton's Cradle like this, five identical balls hang precisely next to each other on a frame. Each ball actually represents a single pendulum. If you let one of the outer balls swing towards the remaining four, something amazing happens. The four balls do not all move slightly, as everyday experience might suggest. Instead, the middle three remain almost still, while the fifth swings out almost as far as the one that was set in motion.
This behavior suggests an elastic transfer of momentum. Because the balls are made of solid material, the forces from the first ball are simply passed on to the last one. It is the only one that moves, as there is no further ball to which it can transfer the momentum. Of course, the whole process does not occur completely without energy losses in the strings, through air resistance, and small inaccuracies in the suspension, so the middle balls also swing slightly. However, the effect can still be observed very well for some time.
The effect of Newton's Cradle is even more astonishing if you let two or more balls swing simultaneously. Then, as many balls move on one side as you released on the other. You can learn more about this in this Wikipedia article.
With Newton's Cradle, you can experience physics live at home and, for example, vividly demonstrate the effects to your children. Therefore, a Newton's Cradle should not be missing in any geek household!
