Given, speed of sound in air, c=300ms−1 Difference between apparent frequency during approach and apparent frequency during recession =2% Thus, frequency during approach - frequency during recession =
2
100
×f0 ⇒f0(
c+v
c
)−f0(
c−v
c
)=
2
100
f0 where, c is speed of sound in air and v is the velocity of source. ⇒