RE DOPPLE, SUPPOSE: Sound travels from a source to a receiver. Both the source and the receiver are devices made by Feeblevetzer. Relative to the air , sound travels at a constant speed: Vwm = 340 m/s. As measured in the air's reference frame, Relative to the air, one of the Veeblefetzer devices travels at a constant speed: Vim = 80 m/s. It is not clearly recalled which device moved relative to air and which did not. The direction of motion is also, alas, unclear. The one clear thing is the sound's frequency according to the source: furs = 800 Hz. Compute and clearly report the received frequency for each of 4 possible cases. Thank you