text: question below? bats emit sounds of frequencies around 35.0 khz and use echolocation to find their prey. if a bat is moving at the speed of 12.0 m/s toward an insect at an air temperature of 20.0oc, (assume the insect and air are still) (a) what frequency is heard by the insect? (b) what frequency is heard by the bat from the reflected sound? (c) would the speed of the bat affect the answers? this is what is called the doppler effect. all you really need to answer this question is a simple equation: f = f0 [(s +/- so)/(s -/+ ss)] where f is the observed frequency, f0 is the frequency of the source, s is the speed of sound, so is the speed of the observer (+ if moving towards, - if away), and ss is the speed of the source (- if moving towards, + if away).