Cave swiftlets are a type of small cave dwelling birds. Like bats, cave swiftlets use echo location to find their way in the the dark. To warn it's family of its approach a certain swiftlet sends out a sound pulse with a frequency of 5.60 kHz. The swiftlet if flying towards the nest with a speed of 13.1 m/s. The speed of sound in air is 342 m/s.
1) What frequency pulse does the family in the nest detect?
2) What frequency pulse does the swiftlet detect reflected from the nest?
3) On detecting the pulse the parent waiting in the nest realises that it is its turn to leave to find food. It flies towards the approaching swiftlet with a speed of 12.5 m/s. What frequency pulse does the swiftlet leaving the nest now detect coming from the swiftlet approaching the nest?
4) What frequency pulse does the swiftlet approaching the nest detect reflected of the swiftlet leaving the nest?