To make our experiment, we need this materials:
A cardboard cylinder
To make or experiments, we need to prepare a pair of sticks tilts with two boxes.
Then we fix two funnels with a sticky, to make our double funnel.
If we drop a cardboard cylinder in the sticks, we can see that it goes down because of the action of gravity. However, if we drop our double funnel in the sticks, we can see it goes up.
If we pay attention, in the upper part of the tiet sticks, it increases the separation of the sticks and it makes that when the funnels roll up, its center of gravity (that coincides with the geometric center) goes down.
So the funnel, the same as the cardboard cylinder, goes down because of the action of gravity.