This question has me very lost.

Two loudspeakers emit sound waves along the x-axis. The sound has maximum intensity when the speakers are 11 cm apart. The sound intensity decreases as the distance between the speakers is increased, reaching zero at a separation of 50 cm. What is the wavelength of the sound?

Also

If the distance between the speakers continues to increase, at what separation will the sound intensity again be a maximum?

I've tried like 5 different ways, none seem to work.

Can someone please how to approach it the correct way.

Thanks in Advance.

2 answers

The difference between 50 cm and 11 cm must be one half wavelength.

I would expect a max at 50+39cm.
1/2 wavelength=zero intensity-max intensity

so your wavelenth is going to be 2(50-11)=78 cm

For the second half of the question, you already know a max is achieved at 11 cm so to find the answer you just add 11cm to your wavelength

78+11= 89 cm