How Do Size and Movement Direction of Insects Affect Bat Echolocation?

[m.l.]

Homework Statement

A bat emits short pulses of high-frequency sound and detects the echoes.
a) In what way would the echoes from large and small insects compare if they were the same distance from the bat?
b) In what way would the echo from an insect flying toward the bat differ from that of an insect flying away from the bat?

Homework Equations

Written Response

The Attempt at a Solution

a) absolutely no clue. maybe more returning sound waves from a larger creature?
b) possibly something about the doppler effect?

 

[astrorob]

Hi m.l.

In regards to a), I think you're probably correct. It seems reasonable that the larger the object, the more intense the reflected sound wave.

In regards to b), I think you're also correct. If the insect is moving away, the echo returned by the object would have a lower pitch due to doppler shift, and vice versa.