State two characteristics of a stationary wave that make it different from a progressive wave.
A loudspeaker emitting sound at frequency $550\ \text{Hz}$ is positioned close to the open end of the tube. The piston is shifted along the tube and a loud sound is heard when the separation $L$ between the piston and the open end is $45\ \text{cm}$. The speed of sound in the tube is $330\ \text{m s}^{-1}$. Show that the sound wavelength in the tube is $60\ \text{cm}$.
On Fig. 4.1, show every displacement node along the tube, using the letter N for each one.
On Fig. 4.1, show every displacement antinode along the tube and label each one with the letter A.
A long tube is open at one end and is closed at the opposite end by a piston that can be moved along the tube, as shown in Fig. 4.1. A loudspeaker emitting sound at frequency $550\,\text{Hz}$ is placed near the open end of the tube. The piston is shifted along the tube and a loud sound is heard when the distance $L$ between the piston and the open end of the tube is $45\,\text{cm}$. The speed of sound in the tube is $330\,\text{m s}^{-1}$.
On Fig. 4.1, mark all the positions along the tube of (1) the displacement nodes (use N), (2) the displacement antinodes (use A).
The frequency of the sound from the loudspeaker in (b) is slowly reduced. Find the lowest frequency at which the tube of length $L = 45\,\text{cm}$ will produce a loud sound.