A 0.5-m tube is placed in a bucket of water. The tube can be moved up and down to vary the length of the column of air inside, and the temperature of the air is 20°C, which corresponds to a sound speed of 343 m/s. A 440-Hz tuning fork is struck and placed over the mouth of the tube. The tube is moved up and down until the first resonance can be heard. What is the length of the column of air inside the tube when one antinode and one node form in the standing wave?