A student investigates the properties of sound waves using a rigid, cylindrical tube of length \( L = 0.60 \text{ m} \). The tube is initially open at one end and closed at the other end by a removable cap. A small speaker is placed near the open end. The speaker is connected to a signal generator that produces a pure tone of variable frequency, creating a standing wave of sound inside the tube. The speed of sound in the air inside the tube is \( v = 340 \text{ m/s} \).