Apparent frequency of reflected wave

[desmond iking]

Homework Statement

A police car P with its siren on is chasing car T . The frequency of the siren is 1000hz. The speed of police car P is 30m/s . and the speed of car T is 40m/s . What's the apparent frequency of the siren heard by driver T > the ans is 967hz . I managed to get the ans for this.
But i didnt managed to get the ans for part b .
here's part b :
What's the apparent frequency of the reflected wave heard by driver T ? the ans is 941 hz. p/s : i assume both P and T are moving to the right.

Homework Equations

The Attempt at a Solution

apparent frequency of the siren heard by driver T = ((330-40)/(330-30))x 1000 = 967hz.

b ) apparent frequency of the siren emitted by P to the left = (330/(330+30)) x 1000 = 917hz.

apparent frequency of the siren reflected from the right and heard by T after reflection = ((330-40) / (330-30) ) x 917hz = 886hz . i am not sure which direction of the sound wave is reflected. can somoene explain on this?

 

[vela]

Are you sure the question is asking about driver T hearing the reflected wave? It makes more sense that driver P hears the wave reflected off of T.

 

[desmond iking]

Are you sure the question is asking about driver T hearing the reflected wave? It makes more sense that driver P hears the wave reflected off of T.

yes the question asking T heard the wave

 

[HallsofIvy]

Driver T can't hear the reflected wave- it is moving away from him.

 

[desmond iking]

Driver T can't hear the reflected wave- it is moving away from him.

so is the question wrong?

 

[vela]

Sounds like it. Try calculating the frequency P hears for the reflected wave.