Given that,
Power = 60 W
Distance = 1.0 m
Distance between speakers = 1.5 m
We need to calculate the intensity
Using formula of intensity
Put the value into the formula
We need to calculate the intensity
Using formula of intensity
Put the value into the formula
We need to calculate the intensity of the sound waves produced by four speakers
Using formula for intensity
Put the value into the formula
Hence, The intensity of the sound waves produced by four speakers is 13.78 W/m².