Question

If a cork is put into a glass of water, the cork will almost always drift to the side of the glass. There is one simple way, however, to get the cork to float in the center of the glass (the horizontal center, not the vertical). What is it? Water, the glass, and the cork are all that is required.

Answer 1

Cork floats to the highest point. If you fill the glass as much as possible, the water will form a convex shape above the glass, with the highest point at its center. This is where the cork will drift to and settle.