What is the speed of the jet at point B based on the given information?

[r4sph4sp]

Please Help Have exam tomorrow! waves

A jet is flying horizontally, as the drawing shows. When the plane is directly overhead at B, a person on the ground hears the sound coming from A in the drawing. The average temperature of the air is 20 °C. If the speed of the plane at A is 164 m/s, what is its speed at B, assuming that it has a constant acceleration?

Please help!

I'd be so grateful!:)

http://univirtual.info/elementaryphysics/pc/cutnell3158c16/cutnell3158c16_17.htm

(watch this page, question number 101 for the drawing)

 

[Stonebridge]

You need the speed of sound to do this. I assume you know this from the temperature.
Write down the formula for the distance the sound travels from point A to the observer in terms of the speed of sound and the time taken, t.
Write down the formula for the distance the plane travels from A to B in terms of its initial and final velocity, and time t.
You have a right angle triangle and a formula for two of the sides and you know one of the angles.