What should be the velocity of a source of sound so that the apparent frequency to a listener will be twice the actual frequency of the source? Velocity of sound in air = v .

What should be the velocity of a source of sound so that the apparent

1.	What should be the velocity of a source of sound so that the apparent frequency to a listener will be twice the actual frequency of the source? Velocity of sound in air = v .
Answer» Solution :Apparent frequency , `N.= (v = u_(o))/(v - u_(s)) XX n` In this case n. = 2N . The listener is stationary, so ` u_(o) = 0 ` the apparent frequency is higher, i.e., the SOURCE is approaching the listenger. So, the velocity of the source ` u_(s) ` is positive . Therefore, ` 2n = (v)/(v-u_(s)) xx n " or " , v = 2 (v - u_(s)) " or " = v/2 ` i.e., the source is approaching the listener with half the velocity of SOUND .