4) (20 pts) You stand halfway between two sound speakers that are facing each other 4 m away. The speakers play the same frequency note and at your location the sound intensity is at a maximum. Assume the speed of sound is 343 m/s. Moving from this point toward one of the speakers you encounter the first minimum of sound intensity when you moved 0.25 m. l a) What is the frequency of the sound? b) If the frequency' IS then increased while you remain 0. 25 m from the center, what is the first frequency for which that location will be a maximum ofI sound intensity