a) Two loudspeakers are placed at either end of a gymnasium, both pointing towards each other. The sound emitted by the speakers are in phase and are of frequency of 256Hz. An observer midway between the speakers experiences an intensity maximum. How far must an observer walk towards one of the speakers to experience the first intensity minimum?
[Note: Speed of sound in air is 343 m/s]
b) The sound level 2.0m from a pneumatic chipper is 120dB. How far from it must you be in order for the level to decrease by 40dB ?
c) What do you understand by beats ?