The Vespertilionidae family of bats detect the distance to an object by timing how long it takes for an emitted signal to reflect off the object and return. Typically they emit sound pulses 3 ms long and 70 ms apart while cruising.
(a) If an echo is heard 60 ms later (v sound = 331 m/s), how far away is the object?
(b) When an object is only 30 cm away, how long will it be before the echo is heard?
(c) Will the bat be able to detect this echo?