Q40S - Superposition of sound waves

What to do
This question is about superposition of sound waves from two loudspeakers. Answer the questions below, showing working where applicable.
The experimental set-up
Two loudspeakers separated by 3 m are connected to a signal generator. They are set up in the open air, well away from buildings. A student stands 10 m from the midpoint of the speakers, hearing a maximum amplitude sound and walks in front of them in the direction shown by OX until the sound drops to a minimum level. This occurs at point X as shown in the diagram.

1.	How much further does sound from speaker B have to travel to reach the student than that from speaker A?

2.	The position X was the point where the student heard the first minimum. How many wavelengths was the path difference between speaker A to X and speaker B to X?

3.	What was the wavelength of the sound?

4.	The speed of sound on that day was 340 m s–1. What was the frequency of the note?

5.	Why should this experiment be performed outside?