A group of friends decide to have a competition so see who can swim to the greatest depth. They hold the competition in the ocean where the density of sea water is 1021 kg/m3. They do not have sophisticated equipment but luckily one of them has been studying physics 1A at UNSW and has the bright idea to use an empty tube, the tube is L = 48.9 cm long and shaped like a cylinder. He wets the sides and then puts some sand in and shakes it around, coating the sides of the container. The friends agree that they will dive down as deep as they can while holding the tube vertically (the bottom is open the top is closed, allowing water to enter from the bottom). The winner of the competition is the one with the most sand washed away. It turns out that the winner manages to wash away 14.2 cm of sand. How deep did the winner dive?

Note: define the depth as the distance from the bottom of the tube to the surface of the water.