A suface receiving sound is moved from its original positionto a position three times farther away from the source of thesound. The intensity of the received sound thus becomes (a) three times aslow. (c) three times as high (b) nine times aslow (d) nine times as high A suface receiving sound is moved from its original positionto a position three times farther away from the source of thesound. The intensity of the received sound thus becomes (a) three times aslow. (c) three times as high (b) nine times aslow (d) nine times as high
Explanation / Answer
given I1 = r1 I2 = 3r1 = r2 we know that I = P/4r2 I1/I2 =(r22/r12) I1/I2 =(3r1)2/r12 ) = (9/1) I2 = I1/9 nine times low . b is correct answer. I1/I2 =(r22/r12) I1/I2 =(3r1)2/r12 ) = (9/1) I2 = I1/9 nine times low . b is correct answer.