Question

You are flying in an ultra-light aircraft at a speed of 41.4 m/s. An eagle, whose speed is 21.7 m/s, is flying directly toward you. Each of the given speeds is relative to the ground. The eagle emits a shrill cry whose frequency is 3680 Hz. The speed of sound is 330 m/s. What frequency do you hear?

I got 3020 Hz, but that's wrong apparently, pls help!!!

Answer 1

the transmitter is coming toward you at a relative speed of 63.1 m/s
You will therefore hear a HIGHER frequency.
http://hyperphysics.phy-astr.gsu.edu/hbase/Sound/dopp.html
f' = [ v/(v-vs) ] f
f' = [330 / (330 - 63.1) ] 3680

Answer 2

F = ((Vs+Va)/(Vs-Ve)) * Fe.
F = ((330+41.4)/(330-21.7)) * 3680 = 4433.2 Hz.

Vs = Velocity of sound.
Va = velocity of the aircraft.
Ve = velocity of the eagle.
Fe = Freq. emitted by the eagle.