Holes and water pressure Cut the top off a 2-quart plastic bottle. Make four holes in it with a nail. Stand the bottle in a large container. Fill the bottle with water with the plastic strip in place to cover the holes. Pull out the plastic strip and observe the results.
Repeat steps a and b.
Now, rotate the jug until you can see the water moving in a vortex. Drop marbles or pebbles onto the surface from different directions and have someone else figure out the direction that you threw the objects by examining the impact trails of the flour.