A tube of length $L$ has both ends open. When a tuning fork oscillating at frequency $f_x$ is placed at one end, a stationary wave is produced in the tube. This is the lowest frequency of stationary wave that can exist in this tube. A second tube of length $2L$ has one end closed. When a tuning fork oscillating at frequency $f_y$ is held at the open end, a stationary wave is produced in this tube. This is the lowest frequency of stationary wave that can exist in this tube. Take the end correction for each tube to be negligible. Which equation is correct?
- A$f_x = \frac{f_y}{4}$
- B$f_x = \frac{f_y}{2}$
- C$f_x = 2f_y$
- D$f_x = 4f_y$