Last Problem:
You have no doubt observed that a cork will always drift over to the side of a water glass and stay there. Can you think of a way to make the cork float in the middle of the glass without touching either the cork or the glass?
Answer:
Fill the glass with water until it forms a convex lip above the rim. Then, place the cork in the glass.
The cork will seek the highest point, which is now in the middle, and stay there.
Today’s Problem:
What happens when you barely touch the edge of a stream of water with a spoon? Why does this happen?