You now put a cap on the bottom of the tube, closing it off and making it water tight. The loudspeaker continues to broadcast at 1372Hz but the tube no longer resonates with this frequency. I orient the tube vertically and slowly pour water into the tube. I listen carefully for the tube to resonate again with the loudspeaker (fixed at 1372Hz) due to standing sound waves in the air above the water inside the tube. How many times will I hear the tube resonate before it is completely full of water