In this video, Dianna from Physics Girl poses one of my favorite fluids brain teasers: if you are in a boat on a lake and you toss a rock from the boat into the water, what happens to the water level? Does it rise, fall, or stay the same? Think about it for a minute, and then check out the video. (The answer may surprise you.) (Video credit: Physics Girl)
Celebrating the physics of all that flows