The following is a neat little experiment whose result may be counterintuitive to some of those who embrace the “all bodies fall the same way inside earth’s gravity” ‘doctrine’ without quite understanding it.

Remember, in old ages long ago people thought that a feather does not fall as fast to the ground as a cannon ball. Nowadays, people are so much smarter, well, at least they feel so much smarter, and they know that the feather only falls slower due to the air resistance. This has become somewhat of a 'doctrine' in the sense that many who 'know' it do actually not really understand the underlying reasons. In result, they are surprised by the nifty little experiment in the linked video: The wooden angle reaches the table long before the ball does not only because they start out a little different but also because the tip of the plank accelerates faster than the freely falling ball (See the golf tee? It Immediately separates from the ball and speeds downwards, leaving the ball behind.).

It is a very simple set-up and a good idea for a project that can involve small children. Older ones may be able to calculate the required lengths of the wooden angle's arms and so on. If the video should not be embedded correctly, you may have to surf to it on the MIT website.

And afterward: Who comes up with the shortest and most philosophical reason for why the ball ends up in the cup?

CLARIFICATION: I am not interested in why the ball is in the cup but in the fact that the end of the arm accelerates more than the free falling ball although much of the force onto the wooden plank just presses on the joint (hinge). (This is necessary for the ball to land in the cup, so I formulated the question above that way, which has misled some readers. Sorry about that. This is really about that the tip accelerates faster, as is proven by the tee separating from the ball at once without dragging it to the side. Moreover, at larger starting angles, all this would not happen!)