I need help!!

Suppose that the aircraft flies at constant heightand constant speed along a flight path which passes directly above the observer. Assume the speed of the sound is Vs=340m/s, suppose that the aircraft travels at Vp (m/s). you may find it more convenient to work with the ratio of these speeds. The ratio Vp/Vs is called the 'Mach number' and is denoted by m. Subsonic flight corresponding to m<1 and supersonic flight to m>1.

Let x be the coordinate of the aircraft and y the coordinate of the apparent source of the sound at any particular time. Choose the positive direction to be that in which the aircraft is travelling, which means that x<0 before the aircraft passes over the observer and x>0 afterwards.

Q:For subsonic flight (eg. m=0.6) and a particular height (eg. h=1250m), choose a value for y and calculate x. (Uf the aircraft emits a sound at some point P, the sound travels towards the observer, but meanwhile the aircraft continues along its flight path.) Generalise your result and hence obtain a formula for x in terms of y (and m and h).